I have a script tool that:   Creates a feature dataset within a file geodatabase Performs a Select by Attributes on a cadastral layer Copies the selected polygons into the feature dataset. The copied polygons are then dissolved to give a property boundary and added to the feature dataset The centroid is then calculated and added to the feature dataset   Now this works fine the first time you run the script. But once you run it for a new property I get the 000210 error whilst trying to copy the selected polygons into the feature dataset. It will create the new feature dataset, but it will not let me copy anything into it. I have tried using personal geodatabases. I have tried outputting to a shapefile and using FeatureClassToGeodatabase tool, all which do not work. BUT if I delete all other feature datasets then it will work. I've checked for locks and there are none. I do not understand what could possibly be going on here  import arcpy, os  #Specify the drive you have stored the NCT_GIS foler on drive = arcpy.GetParameterAsText(0)  #Folders RF_Prop_DB = drive + ":\\NCT_GIS\\DATA\\RF_Properties.gdb" Lambert_Projection = drive +":\\NCT_GIS\\Scripts\\res\\GDA 1994 New South Wales Lambert.prj"  arcpy.env.workspace = (RF_Prop_DB) arcpy.env.overwriteOutput = True lot_DP = arcpy.GetParameterAsText(1).split(';') PropertyName = arcpy.GetParameterAsText(2) #Create the query queryList= [] for i in range(0,len(lot_DP)):     if i % 2 == 0:         lt = lot_DP[i]         DP = lot_DP[i+1]         query_line = """( "LOTNUMBER" = '{0}' AND "PLANNUMBER" = {1} )""".format(lt, DP)         queryList.append(query_line)         if i < (len(lot_DP)):            queryList.append(" OR ") del queryList[len(queryList)-1]         query = ''.join(queryList)   #Create the feature dataset for the property arcpy.CreateFeatureDataset_management(RF_Prop_DB, PropertyName, Lambert_Projection) #Cadastre lotFile = drive + ":\\NCT_GIS\\DATA\\NSWData.gdb\\Admin\\cadastre" #Create lot polygons in feature dataset arcpy.MakeFeatureLayer_management(lotFile, "lot_lyr")  arcpy.SelectLayerByAttribute_management("lot_lyr", "NEW_SELECTION", query) arcpy.CopyFeatures_management("lot_lyr", os.path.join(RF_Prop_DB, PropertyName, "Lots")) #Create property boundary in feature dataset arcpy.Dissolve_management(os.path.join(RF_Prop_DB, PropertyName, "Lots") , os.path.join(RF_Prop_DB, PropertyName, "Boundary"), "", "", "SINGLE_PART", "DISSOLVE_LINES") #Create property centroid in feature dataset arcpy.FeatureToPoint_management(os.path.join(RF_Prop_DB, PropertyName, "Boundary"), os.path.join(RF_Prop_DB, PropertyName, "Centroid"), "CENTROID")

I'm sure there must be a simple reason for this but I can't seem to be able to import a shp file or a feature class from another file or sde geodatabase into a Feature Dataset without getting an error.  The feature classes come in fine if I don't don't try to import them into a Feature Dataset.  The feature dataset definitely has the same projection as the feature classes I'm trying to import so I don't think that's the problem.  The Error I get is ERROR 000210 and just says Failed to convert and cannot create output and Failed to execute (CopyFeatures).    Any ideas what I may be doing wrong here.  Seems like something so simple.  I'm trying to use the Feature Datasets to better organize my data which I think is there purpose.   Update:  So as you can see below, Jason helped me find the answer.   As suggested by Matt below, I added a new Idea to the ArcGIS Ideas site.  Here is the link to that, so please promote this up if you agree a better error message is needed here:


I have a data extension with a customerID and 15 products assigned to them(screenshot attached)    Some of the 15 products are missing the value and I would like to write a query so if Product1 is empty to get the value of Product2 and so on.  i.e. if product1 product3 and product5 are empty to show the first 12 products with the value inherited from the next product and last 3 products to be empty in this case because there is 3 empty products.  Is this possible?

I have a data extension with a CustomerId(PK) that has multiple Productid's as Productid1, ProductId2, ProductId3...ProductId10.   Some of the Productid's are empty for some Customers and I'm trying to write some AMPscript if the productIdx is empty to show the next one.  I'm trying to display 6 products in an email and at the moment when I preview the email, if from the first six Products one doesn't have a value(is empty) I get the error "The subscriber preview failed to generate. Review the details, correct all issues, and try again. Product1 not found"  I want to skip the product that is NULL and go to the next one available.  %%[ SET @customerId = [customerId]  SET @customer_rows = LookupRows("PRL","customerId",@customerId) IF Rowcount(@customer_rows) > 0 THEN SET @customer_row = ROW(@customer_rows, 1)  SET @product_count = 0  SET @productId1 = FIELD(@customer_row, "productId1")  IF NOT EMPTY(@productId1) THEN SET @product_rows = LookupOrderedRows("PI_UK", 1,"Normal_SalePrice Desc", "ProductCode", @productId1)  IF RowCount(@product_rows) > 0 THEN  SET @product_count = ADD(@product_count,1) ELSE  SET @product_count = ADD(@product_count,0) ENDIF ELSE SET @product_count = ADD(@product_count,0) ENDIF    SET @productId2 = FIELD(@customer_row, "productId2") IF NOT EMPTY(@productId2) THEN SET @product_rows = LookupOrderedRows("PI_UK", 1,"Normal_SalePrice Desc", "ProductCode", @productId2) IF RowCount(@product_rows) > 0 THEN SET @product_count = ADD(@product_count,1) ELSE SET @product_count = ADD(@product_count,0) ENDIF ELSE SET @product_count = ADD(@product_count,0) ENDIF  SET @productId3 = FIELD(@customer_row, "productId3") IF NOT EMPTY(@productId3) THEN SET @product_rows = LookupOrderedRows("PI_UK", 1,"Normal_SalePrice Desc", "ProductCode", @productId3) IF RowCount(@product_rows) > 0 THEN SET @product_count = ADD(@product_count,1) ELSE SET @product_count = ADD(@product_count,0) ENDIF ELSE SET @product_count = ADD(@product_count,0) ENDIF  and so on till ProducId10...   I have uploaded a photo with the PRL Data extension


I need an alternative to this simple math.    float FreqA = 28.333334; FreqA = FreqA+0.000001; println(FreqA);   However this results in 28.333336.  How do I perform this math to get the correct answer of 28.333335?  I have tried converting the float to an integer performing the math, than converting back to a float, but I get the same mathematical errors.

Consider the following code:   0.1 + 0.2 == 0.3  ->  false   0.1 + 0.2         ->  0.30000000000000004   Why do these inaccuracies happen?


ChaCha20 along with Poly1305 provides confidentiality and integrity. Now suppose I cascade AES on top of ChaCha20. Is it safe to assume that the Poly1305 MAC is still secure, even if I cascade multiple ciphers? In other words, is one MAC enough to secure both ChaCha20 and AES? Problem solved:

I have heard some people say that the Poly1305 authenticator is a "nuclear" MAC i.e. it is information-theoretically secure. After reading  I see it is based on the Wegman-Carter MAC which is supposedly the natural authentication pairing with the one-time pad cipher.  Is it true though that Poly1305 is really an information-theoretically secure MAC? Here is an excerpt from the paper:     1 Introduction      This paper introduces and analyzes Poly1305-AES, a state-of-the-art secret-key   message-authentication code suitable for a wide variety of applications.      Poly1305-AES computes a 16-byte authenticator Poly1305r(m, AESk(n)) of   a variable-length message m, using a 16-byte AES key k, a 16-byte additional   key r, and a 16-byte nonce n. Section 2 of this paper presents the complete definition of Poly1305-AES.      Poly1305-AES has several useful features:         Guaranteed security if AES is secure. The security gap is small, even   for long-term keys; the only way for an attacker to break Poly1305-AES is   to break AES. Assume, for example, that messages are packets up to 1024   bytes; that the attacker sees 264 messages authenticated under a Poly1305-AES   key; that the attacker attempts a whopping 275 forgeries; and that the   attacker cannot break AES with a probability above δ. Then, with probability   at least 0.999999−δ, all of the 275 forgeries are rejected.   Cipher replaceability. If anything does go wrong with AES, users can   switch from Poly1305-AES to Poly1305-AnotherFunction, with an identical   security guarantee. All the effort invested in the non-AES part of Poly1305-AES   can be reused; the non-AES part of Poly1305-AES cannot be broken.      So it appears Poly1305 is only secure if AES is secure. So in theory if I do not like AES I can swap it out for something else like ChaCha20 (as many have done e.g. SSH and TLS 1.3). However then the authentication is still only as secure as ChaCha20 which in itself is not information-theoretically secure. So then, what if I need an authentication tag that will remain secure for a long period of time (100+ years) and even resist cryptanalysis indefinitely?  I understand the point of the Poly1305 is to re-use the keys for many messages as long as the nonce changes each time. However, assume a hypothetical system which has many one-time pads generated by a HWRNG and they are pre-shared between two parties via a physical exchange. The key material for each message is divided up as follows:   92 byte key for encrypting the 92 byte message using XOR $\oplus$ 16 byte Poly1305 encryption key $k$ (formerly the AES key) 16 byte Poly1305 additional key $r$ 16 byte Poly1305 nonce $n$   So in this scenario the $k$, $r$ and $n$ are unique and truly random per message sent. So per one-time pad encrypted and authenticated message it uses up 140 bytes of true random data. Now given that this construction creates the Poly1305 tag:  Poly1305$_r$($m$, AES$_k$($n$))  Can the AES$_k$($n$) portion be simply replaced with $k$ $\oplus$ $n$? In other words, encrypt the nonce with a one-time pad. Will this remain theoretically secure indefinitely?


What is the combination of rep and timeline used to determine "new contributor" status?  Also, for sites with scaled-down rep requirements for badges, are those rep rep requirements scaled down the same way?  I'm interested in acquiring this hat, and wondering what sites I am eligible to try for it on.

According to :  The new indicator works by the age of a user's first visible post. This could be a question or answer, and the association bonus won't influence the behavior. While you might not be new to our engine, everyone is new when they first join a new community, so the indicator is shown.   How old does one's first visible post have to be for the indicator to be removed?  Is the indicator status calculated on the fly when loading a post, or is it permanently attached to a post and only removed on later posts?  Finally, what happens if the first visible post gets deleted? Is the calculation still based on that post, or is it based on the next post that continues to be visible? In other words, if I posted a few years ago and later post again, and I delete my post from a few years ago, will the indicator start showing up?


I am Indian citizen living in India and holding a Schengen Visa to Germany. Can I able to travel to Romania with Schengen Visa.

I am Indonesian. This month I will go to Iasi, Romania for student exchange. But I will go there after staying one night in France, then take a plane to Iasi, Romania. Do I need to apply for a Romanian visa to enter and stay there for approximately 4 weeks if I already have a Schengen visa issued by France's embassy?


When solving for the value, we know that $e^{\pi i}=-1$ . I am confused as to what is the right answer when you evaluate this.I am getting two possible answers: $e^{3\pi i/2}$ = $(e^{\pi i})^{3/2}$ so this could be $(\sqrt{-1})^3=i^3=-i$ or it could be $\sqrt{(-1)^3}=\sqrt{-1}=i$. Which one is the correct answer, and where am I going wrong? Thanks.

Since $i = \sqrt{-1}, i^2 = -1, i^3=-i, i^4 =1$ I understand to calculate, say,  $i^{999}$ I just have to $i^{999} = i^{4 \cdot 249 + 3} = (i^4)^{249} \cdot i^{3} = -i$ But I have a question here, why can't I do something like $i^{999} = (i^4)^{\frac{999}{4}} = 1$ clearly the answer is wrong, infact everytime I'll only end up with $1$. Can anyone point out which step exactly is invalid and with reasons like why is it wrong.   Which naturally extends the question to, how do you calculate $i$ to the power of any "rational" exponent. Like $i^{743/5}$ or something.  Thanks.


Good day, it seems easy but I still find it difficult to understand why we return to the same spot when we jump despite the Earth revolving beneath us. Can someone explain?

If I'm standing at the equator, jump, and land 1 second later, the  Earth does NOT move 1000mph (or .28 miles per second) relative to me,  since my velocity while jumping is also 1000mph.   However, the Earth is moving in a circle (albeit a very large one),  while I, while jumping, am moving in a straight line.   How much do I move relative to my starting point because of this? I  realize it will be a miniscule amount, and not noticeable in practise,  but I'd be interested in the theoretical answer.


I have added a layer from a delimited text (csv) file.  I now wish to add the usual X, Y and Rotation fields to allow me to move and rotate the layer labels.  However, it doesn't seem possible to edit the attribute table as the edit icon is greyed out for this table.    Can I somehow overcome this problem?

I imported the coordinates from an Excel table. They show as single points as intended. Now I want to add columns to the attribute table, but I'm not able to edit it. I wanted to import the following columns from Excel as well, but that doesn't seem to work either.  Sorry for the noob-question, but I couldn't find anything relating the theme through google and such.  Ok, with pictures then: I want to use that to add columns with information to these       You see, the small pensil thingy is greyed out, so I can't edit anything in this layer and I can't add any information to my points.  If I try Ale suggestion I get this error:


In the servlet, I want to make a call to another system using HttpClient to get a JSON response, and here, I don't want to do any manipulation. Just need to give the response to Ajax whatever JSON response I got from other systems. Here I am just converting InputStream to string and give to Ajax. String text = new BufferedReader(               new InputStreamReader(res.getBody(), StandardCharsets.UTF_8))                 .lines()                 .collect(Collectors.joining("\n"));             response.setContentType(JSON_CONTENT_TYPE);             System.out.println("Resonse-->"+text);             final PrintWriter out = response.getWriter();             out.print(text);             out.flush();  Above code simply converted to string and returned as json as below {     "status": "success",     "data": {         "expiresIn": 1558,         "userId": "xxx",         "countryCode": "US",         "sessionKey": "asd"     } }  But would want to know if this is correct or any other better or faster way to convert InputStream to JSON object to Ajax.

I was surprised to find today that I couldn't track down any simple way to write the contents of an InputStream to an OutputStream in Java. Obviously, the byte buffer code isn't difficult to write, but I suspect I'm just missing something which would make my life easier (and the code clearer).  So, given an InputStream in and an OutputStream out, is there a simpler way to write the following?  byte[] buffer = new byte[1024]; int len = in.read(buffer); while (len != -1) {     out.write(buffer, 0, len);     len = in.read(buffer); }


I have heard this song ,"Ain't no party like a chipmunk party" ,there is a negation in the word Ain't itself, why we need to use no after that .Aren't those two negations cancelling out ?

In my native language, double negations "cancel out". I have been trying to learn English using movies and such things, but double negation confuses me. I see instances when double negation cancels out, and some when they do not.  For example, "I haven't got no money" is interpreted as "I have no money." "There wasn't anyone who didn't enjoy the party" is interpreted as "Everyone enjoyed the party."  Is this context dependent? If so, how does one decide which interpretation is correct?


I am booked to go from Dublin to Hong Kong with Turkish airlines with a stopover in Istanbul.  There is a long layover, and I was wondering if anyone knows if I can leave the airport and head into Istanbul itself, and if so, is 7 hours long enough?

I'm flying to Barcelona from Israel via Istanbul. The layover in Istanbul is 12 hours, and I'm thinking about leaving the airport and entering the country for a couple of hours. Would that be possible? Are there any Border/Airline restrictions?  I'm Traveling with Turkish airlines, and hold a passport which does not require a visa to enter Turkey.  I've done this in the past, but only inside the Schengen area, so this question is Turkey-specific.


Today one guy asked a Mac OS-related question on Stack Overflow. Here is the link of the question:  I want to mark it for closure and move it to , but on the options list there was no way to select this site apart from Super User and Server Fault How can I chose ? Here is the screenshot of the options:  Also the This question belongs on other site in the Stack Exchange network has following options:

Possible Duplicate:             When I select Off topic option in Vote to close it shows only few options. I know that this question belong to .   How can I select that option to tell the OP to ask there?  The close window shows the below options:   Meta Stack Overflow  Server Fault  Super User Tex Stack Exchange DBA Stack Exchange   How to add other option?


Measurement of the expansion of the universe is based, in part, on the red shift of light. The speed of light is a constant, although some people argue that it may be changing over time, I am going to ignore that argument for now. But light can lose energy to gravity. In other words, if you look light from a large mass, it will be red shifted by the gravity of the mass. So, while light from our sun travels at the same speed all across the solar system, it is red shifted at the edge of our solar system.  So, does the red shift used by Hubble come from expansion or from gravity?  Are we measuring expansion by assuming that light does not lose energy to the gravity it has escaped?

I was thinking that maybe photons loss energy naturally when they travel great distances.  Or maybe the mass of all matter is increasing over time and therefore photons emitted in the past are necessarily less energetic.  Or is the expansion of space backed up by so much other evidences that trying to find another explanation is completely foolish?


We have to find      $$g(x)=\cos{x}+\cos{3x}+\cos{5x}+\cdots+\cos{(2n-1)x}$$   I could not get any good idea .  Intialy I thought of using   $$\cos a+\cos b=2\cos(a+b)/2\cos (a-b)/2$$

Possible Duplicate:          Prove $$\cos(\alpha) + \cos(\alpha + \beta) + \cos(\alpha + 2\beta) + \dots + \cos[\alpha + (n-1)\beta] = \frac{\cos(\alpha + \frac{n-1}{2}\beta) \cdot \sin\frac{n\beta}{2}}{\sin\frac{\beta}{2}} $$


I'm trying to make sense of the  tag. It has no description, and the questions tagged with it are all over the place - filtering rows in SQL, limiting access to certain devices/activities, defining the allowed input values for programs, etc., etc.  With such a wide range of topics, does this tag make sense to anyone, or should it just need to be burniated?

Can we burn all forms of the  tag? Its too vague of a term.


I'm trying to replace the front rigid fork on my Marin 1993 Palisades Trail with a suspension fork so that when I ride mountain trails I don't destroy my wrists. Does anyone have any suggestions on what suspension forks I can use to replace my rigid one with? It's a 26" tire with what I believe is a 24" frame.  Update: the steerer width is 1 1/8" inch and its threaded.

I have a 1990s Saracen PowerTrax. Is there a way I can install a suspension fork, or will that muck up the bike somehow? I'm actually interested in ways to raise the bars with respect to the seat, so that wouldn't be a problem. My toes rubbing in the wheel, in the other hand, would definitely be a problem.


I'm confused.  As the King of Aquitaine, I had a vassal Countess of Foix. Her heir was Count of a single county in France (both nations are Elective Gavelkind). I had a Vassal Inheritance Warning, which makes sense; when the countess dies, her title would pass to her heir, who would add it to his French title, that being older.  So I created the Duchy of Toulouse and granted it to my Countess of Foix. I figured that this way, when she died, both titles would pass to her heir, and he'd bring his French county to over to join his higher Aquitainian Dukedom.  But when Comtesse du Foix / Duchesse du Toulouse kicked the bucket, I lost Foix to France, and another vassal held Toulouse. Is this an effect of the succession laws? Did one title pass to one heir, and the other to another heir? Could I have seen that, and prevented it somehow?

I have a duke who has a married a foreign duke which has given me an inheritance warning.  This being Crusader Kings, my gut instinct is to have someone killed but I'm not sure who or in what order people must die.  The breakdown is thus: I am playing a Byzantine emperor with high crown authority (shouldn't that prevent titles from leaving the realm?) with a male duke of Jazira reporting directly to me.  He has married (non-matralinially) the duchess of Orkney who is a direct vassal of the King of Norge.  They have two male children together.  My first thought was to kill my own vassal duke so that his son inherits his duchy and the son becomes my vassal.  Then when his mother dies he inherits Orkney which becomes part of my empire since he's already my vassal (at least I think that's what will happen).  That's when I noticed a final confusion in the matter, the duchess and duke have different heirs.  Their elder son is the heir to the duchy of Orkney while their younger son is the heir to the duchy of Jazira.  I am guessing this has something to do with the differing inheritance laws of the two duchies, the duchy of Jazira has primogeniture succession while Orkney has gavelkind.  All I want is to keep the duchy of Jazira under my control, I don't want Orkney, I have enough problems as it is without it.  Who should die to make sure this happens?  I suppose I'd accept non-murderous solutions as well, there's a first time for everything.


I want to solve the equation: $$ x_1 + x_2 +...+ x_n = s \\ \text{where }\ 0 < x_i \le c  $$ Or to rephrase the question count number of ways to break number $s$ in to $n$ numbers where each number is between $1$ to $c$. Without upper bound $x_i < c$ I can use stars and bars method. But since i have upper limit can i still use same method with some modification? Or can you reference me to some other method which can help me solve this.

The problem of counting the solutions $(a_1,a_2,\ldots,a_n)$ with integer $a_i\geq0$ for $i\in\{1,2,\ldots,n\}$ such that $$a_1+a_2+a_3+....a_n=N$$ can be solved with a stars-and-bars argument. What is the solution if one adds the constraint that $a_i\leq r_i$ for certain integers $r_1,\ldots,r_n$?  e.g. for $n=3$, $N=6$ and $(r_1,r_2,r_3)=(3,3,2)$, the tuple $(a_1,a_2,a_3)=(2,3,1)$ is a solution, but $(2,1,3)$ is not a solution because $a_3=3>2=r_3$.


What would the intuitive explanation be?  Would it be because there are infinately many values and so the probability of any specific value is infinitely small hence we say 'close enough' to 0?

My understanding is that a random variable is actually a function $X: \Omega \to T$, where $\Omega$ is the sample space of some random experiment and $T$ is the set from which the possible values of the random variable are taken.  Regarding the set of values that the random variable can actually take, it is the image of the function $X$. If the image is finite, then $X$ must be a discrete random variable. However, if it is an infinite set, then $X$ may or may not be a continuous random variable. Whether it is depends on whether the image is countable or not. If it is countable, then $X$ is a discrete random variable; whereas if it is not, then $X$ is  continuous.  Assuming that my understanding is correct, why does the fact that the image is uncountable imply that $Pr(X = x) = 0$.  I would have thought that the fact that the image is infinite, regardless of whether it is countable or not, would already imply that $Pr(X = x) = 0$ since if it is infinite, then the domain $\Omega$ must also be infinite, and therefore  $$Pr(X = x) = \frac{\text{# favorable outcomes}}{\text{# possible outcomes}} = \frac{\text{# outcomes of the experiment where X = x}}{|\Omega|} = \frac{\text{# outcomes of the experiment where X = x}}{\infty} = 0$$  What is wrong with my argument?  Why does the probability that a continuous random variable takes on a specific value actually equal zero?


How can one find out the value of $43^{1234567890} \mod 22\;?$  Can I just say that because $123456890$ is an even number I can calculate $43^2 \mod 22$, which is $1$?

How do I efficiently compute $a^b\bmod c$:  When $b$ is huge, for instance $5^{844325}\bmod 21$? When $b$ is less than $c$ but it would still be a lot of work to multiply $a$ by itself $b$ times, for instance $5^{69}\bmod 101$? When $(a,c)\ne1$, for instance $6^{103}\bmod 14$?  Are there any other tricks for evaluating exponents in modular arithmetic?  This is being asked in an effort to cut down on duplicates, see  and .


Looking for a decent alternative to the DDI Builder, ideally a free browser version. Currently using  and it's decent, but I'm just a guy that likes options.  I've seen a , but it's 2yrs old. I looked at a few of the options but found mostly PDF stuff. Currently playing on roll20, so I like the idea of being able to share a link back and forth with the DM.  Thanks.

Is there an interactive web-based character sheet for Dungeons & Dragons 4E like there is for  I'm not looking for a character builder.  Mod note: Several of these answers refer to services which no longer exist (or have moved), but as we  they will not be fixed and are kept up primarily for archival reasons.


I would like to have several subscripts in my sum, like "sum over all i but not for i = 3". I have tried using \subscript from amsmath but failed with undefined control sequence. I've also failed to use the subarray environment. Please tell me what is a step by step proper way to have several subscripts?

I'm reading about inverse limits, and the notation sometimes requires some sort of index or set over which to take the inverse limit. It looks something like this:    How would I correctly TeX that? I tried something like             {\lim_{\longleftarrow}}_{H\in\mathscr{F}} but the arrow and the set are side by side, not one over the other.


Is this just a redundant act, or are there differences?

I cannot upvote my own stuff (questions or answers). Why is it that I can mark my own question as a favorite?  Isnt that like upvoting it?  Wouldn't common sense dictate that, as it is my question, it is one of my favorites; i.e., something that I am interested in?


Let $U$ and $V$ be modules over a commutative ring $K$. Is the canonical map $U^* \otimes V^* \to (U \otimes V)^*$ always injective?  I'm a differential geometer so I'm usually dealing with finite-rank locally free sheaves of modules where this is an isomorphism---I'm not very familiar with the weirdness that can happen in more general modules over other commutative rings.

Let $R$ be a commutative ring with $1$. For all $R$-modules $V,W$ we have a canonical $R$-linear map $V^{\vee}\otimes W^{\vee}\longrightarrow (V\otimes W)^{\vee}$ from tensor product of dual modules into the dual of tensor product. My question is, why is this map always injective?


While I tried to prove a problem,          Suppose that a linear fractional transformation carries one pair of concentric circles into another pair of concentric circles. Prove that the ratios of the radii must be the same.      Following is my try     Suppose concentric circles $z_1=\alpha+Re^{i\theta}$ and $z_2=\alpha+t Re^{i\theta}$, where $t>0,\ \theta\in [0,2\pi)$, through LFT $\frac{az+b}{cz+d}$ mapping to          $$     \omega_1=\frac{a Re^{i\theta}+a\alpha+b}{cRe^{i\theta}+c\alpha +d};\\   \omega_2=\frac{a tRe^{i\theta}+a\alpha+b}{ctRe^{i\theta}+c\alpha +d}.    $$      According to condition the mapping maps the concentric circles to concentric circles, so $\omega_1$ and $\omega_2$ are concentric. Suppose $\omega_1=\beta_1+R_1e^{i\theta}$ and $\omega_2=\beta_2+R_2e^{i\theta}$, solve the equations, we get the results as follows,         $$   \beta_1\to \frac{(a \alpha+b) (\alpha c+d)-a c R^2}{(\alpha  c+d)^2-c^2 R^2},R_1\to \frac{R (a d-b c)}{(\alpha  c+d)^2-c^2 R^2};    $$         $$   \beta_2\to \frac{(a \alpha+b) (\alpha c+d)-a c R^2 t^2}{(\alpha c+d)^2-c^2 R^2 t^2},R_2\to \frac{R t (a d-b c)}{(\alpha c+d)^2-c^2 R^2 t^2}.    $$           We simplify $\beta_1-\beta_2=0$, that is          $$     c(c\alpha+ d)=0.    $$   (i)$c=0$, $R_2/R_1=t$.      (ii)$c\alpha+d=0$, $R_2/R_1=1/t$.   Now my question is the first situation is normal and second one seems like the original proposition is not right, what's wrong?   Besides, I think my way to solve this question especially solving the equations are complicated, it there any other simpler solution? Thanks!

Given a Möbius transformation that maps one pair of concentric circles to another pair of concentric circles, why is the ratio of the radii preserved through the map?   I thought about how Möbius transformations are compositions of rotations, scaling, inversion, and translation, and that intuitively, these types of maps shouldn't change the ratio of radii between two circles.   Would it be correct to just say that if $\frac{r_1}{r_2}$ is the ratio of radii between the two circles, then   1) The radii are invariant under translation, $z \mapsto z+a$, so $\frac{r_1}{r_2}$ stays the same  2) Under scaling by a factor $z \mapsto az$, $\frac{ar_1}{ar_2} = \frac{r_1}{r_2}$   3) Under inversion, $z \mapsto \frac{1}{z}$, $\frac{1/r_1}{1/r_2} = \frac{r_2}{r_1}$  Or is there a different/better way to think about this problem?


Is a simple example in order to use some static field in a class.  #ifndef FOOCLASS_H_ #define FOOCLASS_H_  #include <string>  class FooClass {  public:     FooClass();     virtual ~FooClass();      std::string getMessage();      void modifier();     static void modifier_st();     static std::string getStaticMessage();   private:     static std::string message_static;     std::string message;   };   and cpp file with implementations of methods is    #include "FooClass.h"    FooClass::FooClass() {       message = "";   }    FooClass::~FooClass() {       // TODO Auto-generated destructor stub   }    std::string FooClass::getMessage(){       return "Message is:" + message;   }    void FooClass::modifier(){       message += " sample ";   }    void FooClass::modifier_st(){       message_static += " sample static ";   }    std::string FooClass::getStaticMessage(){       return "Message is:" + message_static;   }   #endif /* FOOCLASS_H_ */   I compiled that code with g++.   In the last methods appear error "undefined reference to `FooClass::message_static[abi:cxx11]'".  What is the explanation of that error? What other alternatives is to develop last two methods?

Can anyone explain why following code won't compile? At least on g++ 4.2.4.  And more interesting, why it will compile when I cast MEMBER to int?  #include <vector>  class Foo {   public:       static const int MEMBER = 1;   };  int main(){       vector<int> v;       v.push_back( Foo::MEMBER );       // undefined reference to `Foo::MEMBER'     v.push_back( (int) Foo::MEMBER ); // OK       return 0; }


In the 2009 film , British intelligence agent Archie Hicox is meeting a German spy in a tavern, but his unusual accent catches the attention of Gestapo officer Major Dieter Hellstrom. The two banter back and forth for several minutes, with Hellstrom attempting to catch Hicox in a lie. Finally, Hellstrom orders a bottle of scotch and asks Hicox how many glasses. Hicox orders three glasses, saying "Drei glasse", and holding up three fingers as he does so. After the drinks are delivered,      Hellstrom pulls his pistol under the table and states that Hicox just gave himself away. leading to a fast-paced shootout scene.   As far as I can tell, Hicox's use of German was correct, so I'm thinking perhaps the gesture of three fingers was behind the Major's behavior. After repeated viewings, however, the answer still eludes me.  What about the drink order alerted Major Hellstrom?

In Inglorious Basterds, Lt. Hicox is an English officer who speaks German fluently yet with a mild accent. Speaking a language fluently requires a lot of practice with native speakers and so spending a lot of time with them. So I'd expect that he should know German culture well enough to not order "three glasses" with a wrong gesture (which was the key to the failure of his covert operation).  How is it possible that he speaks German fluently (and so had exposure to native German speakers) and then gives himself away by using the wrong gesture?


I'm only able to install new tool in my local directory.  After ./configure --prefix=/local/directory, new tool is installed my local bin.  But by default it's still point to the old version.  How to force csh to use local installed version?

Recently, I have installed an application (gnuplot) under user directory (/home/usr/bin). I want to run the application whenever I type 'gnuplot' in any directory. What could I do?  I tried to set the path in ~/.cshrc by  setenv gnuplot /home/usr/bin/gnuplot   but it doesn't work. It reports "command not found" as I type gnuplot in the terminal.


Let $x > 1$ and $a$, $b$ be positive integers. I know that $a$ divides $b$ implies that $x^a - 1$ divides $x^b - 1$. If $b = qa$, then  $$x^b - 1 = (x^a)^q - 1^q = (x^a - 1)((x^a)^{q-1} + \ldots + x^a + 1).$$  I'm interested in the converse of the statement. If $x^a - 1$ divides $x^b - 1$, does this imply that $a$ divides $b$?


I don't remember ever seeing suicide used as a standalone verb. I've always seen it as commits suicide or committed suicide.  Can you conjugate and use suicide by itself?

One of the examples in my English composition book (for learning to write my language's sentences in English) was "Why he committed suicide under such a good circumstance is an unsolved question.", but what I would have written would have been "Why he suicided...".  What's the difference between "commit suicide" and "suicide"?  (I think I saw 'commit suicide' more than just 'suicide', and the spell checker of Google Chrome says that 'suicided' is not a  word, even though I think it .)


I didn't see a duplicate..  The motivation is you tube.  Tanton lectures of which one is titled " The Complex number i is NOT the square root of negative one".  Does anyone have a clue why this may be true. I did not follow his one line explanation of why  the square root of negative one is plus or minus i,  not i   Thank you

this is something that came up when working with one of my students today and it has been bothering me since.  It is more of a maths question than a pedagogical question so i figured i would ask here instead of MESE.  Why is $\sqrt{-1} = i$ and not $\sqrt{-1}=\pm i$?  With positive numbers the square root function always returns both a positive and negative number, is it different for negative numbers?


This question is similar to , but is generalized for rectangular matrices. Suppose we have matrix $\bf{S} \in \mathbb{R}^{m \times n} $ and vector $\bf{y} \in \mathbb{R}^{n}$. $\textbf{y}$ is sampled from a multivariate normal distribution with $\Sigma = \sigma^2 I$, where $\mu$ and $\sigma$ is known: $$ \textbf{y} \sim \mathcal{N}(\mu, \sigma^2 I) $$ $\textbf{S}$ is a fixed, known matrix What is the variance of the product of $\textbf{Sy}$? What I have tried so far (attempted working off of ): \begin{align*} \mathrm{Var}(\textbf{Sy}) &= \mathbb{E}[(\textbf{Sy})^2]-\mathbb{E}[(\textbf{Sy})]^2\\ &= \mathbb{E}[(\textbf{Sy})^T\textbf{Sy}]-\mathbb{E}[\textbf{Sy}]^T\mathbb{E}[\textbf{Sy}]\\ &= \mathbb{E}[\textbf{y}^T\textbf{S}^T\textbf{Sy}] - \mathbb{E}[\textbf{y}^T\textbf{S}^T]\mathbb{E}[\textbf{Sy}] \end{align*} From here, it seems I would like to remove $\textbf{S}$ from the expected value, but I am not sure how to proceed.

$\newcommand{\Var}{\operatorname{Var}}$In this  is claimed that if the equation of errors in OLS is given by: $$u=y - X\beta$$ Then in the presence of heteroscedasticity the variance of $u$, will not be constant, $\sigma^2 \times I$, where $I$ is an identity matrix, but: $$\Var(u\mid X)=\sigma^2\Omega$$ In order to account for the heteroskedasticity, we can estimate the transform system, such that $P$ is a transformation matrix. $$Py=PX\beta-Pu$$ Where "the variance of a constant matrix $P$ times a random vector $u$" is: $$\Var(Pu\mid X)=P\Var(u\mid X)P'=P(\sigma^2\Omega)P'$$ Can somebody explain me the proof for that?


If $U$ is an open set in a topological space, is it true that $U$ is the interior of the closure of itself?   If $U$ is open, it must be the interior of itself. But is it the interior of the closure of itself? In the closure, we include all points $x$ such that any open set containing $x$ also contains a point in $U$. In the interior of the closure, we take the union of all open sets contained in the closure.

The question is is the interior of closure of an open set equal the interior of the set?  That is, is this true:  $(\overline{E})^\circ=E^\circ$  ($E$ open)  Thanks.


I’m trying to put a black dot right in the middle of this sphere, but  nothing appears when I click down on my map. Does anyone know what I’m doing wrong?

Before 2.8, it was possible to change the mode of the UV editor to "draw" (I don't know the exact name) and thereby texture paint within the UV editor. The option has disappeared in 2.8. How can I draw in the UV editor or image editor?  I used Windows Paint to make the thin lines, but we don't have the various texture types there, so it's not an alternative solution.  Solution:


Is the inverted image formed in optical bench experiment using two pins and convex lens real or virtual ?  how am i able to see it without screen if it is real ?  we clearly see an inverted image of needle, but it appears to come from behind the lens rather than from air where real image should form. so it must be virtual ?

We're told that a real image is formed when light rays actually converge to a point. That's all good. But what happens if a screen isn't there to take the image on? Is it still there?


I am trying to have an applescript run every 2 minutes that would open sound preferences, then change the audio output by pressing the up key, followed by the down key.  I am using a TV for external audio and it is creating some static but if I change the audio output to a different source and then back again, the static is gone for a random period of time.  I am not a Mac user and have never created an applescript before.  Searching around, this is the closest I can get but still gives me an error when I try to compile.  I am on Mohave.  tell application "System Events"   delay 0.5   keystroke space using command down   delay 0.5   keystroke "Sound"   delay 0.5   keystroke return   delay 1   keycode "125"   delay 1   keycode "126 end tell

I am brand new here and I have an additional clarification or need additional help for an issue from this thread -   In my preference pane, in addition to Headphones and Digital out, I also have 2 apple monitors and would like the option of selecting one of them as out put (namely the first one in the list).   Basically I need help with adjust his solution to be able to select the third row or first monitor as sound output.  Or a way to accomplish this without knowing how to edit AppleScript for a different setup.


I am working on a simple project in C where I encountered this statement in one of the tutorials.  int i = 1 << 2 ;      What does this statement actually do?

I've been attempting to learn C in my spare time, and other languages (C#, Java, etc.) have the same concept (and often the same operators) ...   What I'm wondering is, at a core level, what does bit-shifting (<<, >>, >>>) do, what problems can it help solve, and what gotchas lurk around the bend? In other words, an absolute beginner's guide to bit shifting in all its goodness.


I have a server, running multiple instance of tornado web sites on different ports. for example: 127.0.0.1:8000 127.0.0.1:8001 127.0.0.1:8002  Is it possible to assign each one a domain?

This is a  about DNS/Hostnames resolution to IPs/Ports   Example 1  I'm running a web server on port 80 and another on port 87. I would like to use DNS so that www.example.com goes to port 87. How can I accomplish this using DNS only?  Example 2  I'm running a service on my server on a non-standard port. How can I get clients to connect to this non-standard port automatically? Can I use DNS? Is there some application specific support where DNS could indicate the IP and Port?   Example 3  Do some application protocols specifically support hostname awareness, and allow special actions to be taken based on this information? Are there other questions on Server Fault that cover some of these?  Commandeering: This question was originally asking about running IIS and Apache on the same server, but the same concepts can be applied to any server software receiving connections from clients. The Answers below describe the technical problems and solutions of using DNS and application protocol support to assign a port number for a client to connect.


Sometimes I see something like it, in a class in Android:  static {     foo(); }    What does this do?  Why?

My question is about one particular usage of static keyword. It is possible to use static keyword to cover a code block within a class which does not belong to any function. For example following code compiles:  public class Test {     private static final int a;         static {         a = 5;         doSomething(a);     }     private static int doSomething(int x) {         return (x+5);     } }   If you remove the static keyword it complains because the variable a is final. However it is possible to remove both final and static keywords and make it compile.   It is confusing for me in both ways. How am I supposed to have a code section that does not belong to any method? How is it possible to invoke it? In general, what is the purpose of this usage? Or better, where can I find documentation about this?


I'm making a minigame where a player has to survive in essentially a world of hell. I am creating a "water bar", where players must drink to survive. It is a dummy scoreboard objective. I want to run the command     "/scoreboard players @p remove water 1" every 3 minutes so players can run out of water. The current loop I have is a circle loop () but much bigger than the one shown. Is there a way I can make a loop that's much smaller than the one I have currently but still sends a signal to the command block once every 3 minutes?

The only things I've found so far are a cart method (which ceased working in 1.6), a dispenser method (utilizing the decay on dropped items, but this requires occasional feeding), and a binary counter (which won't work for a single input but rather a fluctuating one).  I want to have a circuit that when I apply an input signal, the output signal doesn't change for 2 to 5 minutes.  When the input turns off, I again want a 2 to 5 minute delay.  I could accomplish this with (roughly) 240 to 600 redstone repeaters, but this is far in excess of being useful.  The only method I can think of, but would require a XOR gate (on the button-input and final output) to start and stop a clock attached to a binary counter.  While I can make room for a device of this size, I was hoping for something simpler.


So I just got done killing a dragon with Farkas, So I go back to the companions, and they start fighting me! I did nothing wrong, and im very confused- is it a bug? It’s only two people. Farkas and his twin brother seem cool, there just staring at me- what do I do? I’m playing Skyrim on Xbox. This is random-but for some reason, I’m in love with Farkas, anyone else?

So, I was using Eorland Gray-Manes forge without causing any harm and all of a sudden I see loads of red dots on my map and it was the Companions and then even Eorland started attacking me. The Guards didn't do anything but cheered: "A Fight!" I even saw Vignar Gray-Mane attack me too. I have a bounty but it wasn't in Whiterun.


Do I have to apply more thermal paste to put the processor heat sink back into the laptop? OR, do I just need to make sure that the screws are tight, and it will work?  What are the problems with not applying more paste?    Also, if I do need to do so, how do I apply it? Just put some on and stick it together?  Thanks!

If I remove the heatsink from my processor temporarily, then later put it back without changing the heatsink or CPU, do I need to reapply thermal paste?


Let $G = A_5.$ Prove that $\langle (1,2)(3,4), (1,2,3,4,5)\rangle = G$ . State clearly any properties of $A_5$ you use.   So I know $A_5 = \{\sigma | \sigma \in S_5$ and $\sigma$ even permutation$\}$.  I'm trying to expand $\langle (1,2)(3,4), (1,2,3,4,5)\rangle$ to show that it equals $A_5$ but I'm not getting the answer.  $(1,2)(3,4)(1,2)(3,4) = (1)$  $(1,2)(3,4)(1,2,3,4,5) = (1,3,5)$ But this is odd, so it wouldn't be in $A_5$.  How do I approach the question correctly?

I'm trying to show the following     $\langle (1,2)(3,4), (1,2,3,4,5) \rangle = A_5$   I managed to prove this but I think my solution is very inelegant. Here's my argument  let $J = \langle (1,2)(3,4), (1,2,3,4,5) \rangle,$ then $\lvert J \rvert \geq 8$ and $\lvert J \rvert$ divides $\lvert A_5 \rvert = 60,$ so the possibilities are  $\lvert J \rvert = 10, 12, 15, 20, 30, 60$.  Then I sat down and calculated 13 more elements of $J$, so now the possibilities are $\lvert J \rvert = 30$ or $60$. But we can't have $\lvert J \rvert = 30$ because then $J$ would be normal (index 2 theorem) which would contradict $A_5$ being simple, so we must have $J = A_5$.  The calculation part make this proof quite long winded, is there a simpler way of getting the result?


Let $\tau$ be the topology on $\mathbb R$ generated by the basis $\{(a,b] : a,b \in \mathbb R\}$ , then is it true that any basis for $(\mathbb R,\tau)$ must be uncountable ?

I am trying to prove that $\mathbb{R}$ with the lower limit topology is not second-countable.  To do this, I'm trying to form an uncountable union $A$ of disjoint, half-open intervals of the form $[a, b)$, $a < b$. Is this possible? I think this would imply the $A$ is open but no countable union of basis elements could coincide with $A$ therefore making the real numbers with the lower limit topology not second-countable.  I think there must exist something like $A$ described above but I am having trouble visualizing it and coming up with a formula to represent it.  Maybe there is some other way to show it is not second-countable.


Why some superusers(users with awesome reputation points) have Unicorn as profile pic?  I don't understand philosophy behind it.  You can check yourself ->                       Don't know how many more users are here with Unicorn.

Based on , I have started building a unicorn avatar maker. It's still quite ugly, and the results aren't different enough yet, but this is what it looks like so far:  /  (removed the images from here to make this thing a little shorter). Is this just way too stupid, or should I go on? If so, any suggestions? I'm thinking of things like backgrounds etc.  Updates Update 2010/01/30: Version 0.2. Now prettier and with legs, rainbows, and stuff. Examples: Æther:  (source: ) Jeff Atwood:  (source: ) Troggy:  (source: )  Update 2010/01/31: Still version 0.2, the images are (almost) unchanged. But now its on the App Engine for everyone, so go ahead pounding my quota: https://unicornify.appspot.com/avatar/HASH?s=32 Replace HASH by the md5 hash that gets given to gravatar (or any hexadecimal number, really). Don't just copy & paste the above into your browser. I thought this was clear, but looking at the access logs, it looks like I have to explain it. The ?s=32 parameter can be omitted. The only legal values are 32 and 128; defaults to 32. Other parameters are ignored. If you take  and change the substitution line to $(this).attr("src", $(this).attr("src").replace(/www\.gravatar\.com/, "unicornify.appspot.com"));  you'll see meta the way it has been looking to me for the past days: Full of unicorns. If you just want to replace the identicons, i.e. those users that don't have their own gravatar set up, use this instead: $(this).attr("src", $(this).attr("src").replace(/(www\.gravatar\.com\/avatar\/)([a-z0-9]*)\?s=(\d+)&d=identicon(.*)$/, "$1$2?s=$3&d=http%3A%2F%2Funicornify.appspot.com%2Favatar%2F$2%3fs%3d$3$4"));  Finally, if you just want to see it once, without any greasy monkeys: Paste this javascript:(function(){$("img").attr("src", function(){return this.src.replace(/www\.gravatar\.com/, "unicornify.appspot.com")})})()  into your location bar.  Update 2010/02/14: Version 0.4 I will be deploying a new version later today. Some of you have showcased your own unicorn avatar below using a direct link to unicornify.appspot.com/avatar/.... These images will then show the updated version. If you want to preserve the historical record by keeping the old version, you'll have to host the image somewhere else, or at least change the image URL. The old ones will be available by passing an additional parameter v with the value 3, i.e. https://unicornify.appspot.com/avatar/HASH?s=32&v=3 No new old-version images will be created, but the previously created ones will still be available for a while. Since the unicorns have their own website by now, this is probably the last update I'll be posting on this question.  Update 2010/04/01 Jeff finally rolled out the Unicorn avatars for us all to enjoy.


Chronology and other relevant information I read it at the latest in the mid 90s, which means it would most likely written before that. I remember multiple books, none particularly large. Plot Points  It involved the main protagonist who initially discovers he has the power to control fire (Which is rare but not impossible - someone refers to him as a "Firebrand") but eventually discovers he has more broad elemental powers which was either unique or at least ultra rare.  He gets together with other people with these powers to overthrow some sort of evil.  I think one of his companions had some control over poison.

This is a book I read as a child, so sometime in the 1980's  . It was actually a two part book series, both normal novel length. It was a swords and sorcery style setting.  Details are sketchy, but I'll give you what I can remember.  It centred around  a boy on a quest against some demon-like villain wizard type character. At some stage a girl was kidnapped and they were off to rescue her ( fairly generic stuff)  . I think the girl also had magic powers, healing I think.  This boy could control the weather or elements. He encounters a monk type character who ends up travelling with him and becomes a teacher of sorts. This monk is actually blind, but can still sense his surroundings, DareDevil style. ( I cannot remember if this was a magical ability or just something the monk had developed over time. ). I seem to remember this character had black, reptilian style eyes.  There may have been more people travelling with them I don't recall.  I recall the encounter with the main enemy took place on the top of a mountain, this mountain had the top taken off so was perfectly flat. ( I hope I'm not getting muddled with a different book with this detail)  The baddie know the boy could only control the elements if he was exposed to them, so ended up sealing the room he was fighting in so the boy had no contact with the outside. He won through by using a dagger or sword to make a crack in the floor through the protection, giving him enough of a connection with the outside to use his powers. I /think/ he died during this battle, and the girl they were rescuing brought him back to life. ( Or maybe she dies, and was brought back to life somehow)


I've seen this a couple times. What does the part where y is over k with a space between them? What does this imply? (Below is the Binomial Theorem equation)  $$(x + a)^y = \sum\limits_{k=1}^{\infty}\binom{y}{k}x^ka^{y-k}$$

What do the parentheses next to the summation involving the binomial coefficients mean? Like this: $$\sum  _{i=0}^{n} \binom{n}{i}a^{(n-i)}b^i=\left(a+b\right)^n $$


I think the answer is yes because otherwise $f$ wouldn't be a function. Is this correct? And how would the formal proof go?

Prove that   injective function $f:X\to Y$ exists surjective function $g:Y\to X$ exists   is equivalent.$(x,y\neq \emptyset)$   My approach  First,prove left to right.  If injective function $f:X\to Y$ exists, a set A can be defined like this. $$A=\{f(x):x\in X\}$$ then it is sure that $A\subset Y$, and $|A|=|X|$  And, if we define function $g$ like $$g(y)=\begin{cases}x & \text{if $y\in A$ and } f(x)=y,\\x_0& \text{if }y\notin A.\end{cases}$$ ($x_0$ is a fixed element of $X$)  Then, $g$ is a surjective function, so surjective function $g:Y\to X$ exists.  Now,prove right to left.  If surjective function $g:Y\to X$ exists, $\forall x \in X$, we can select a element $y\in Y$ that $g(y)=x$, which is clear that we can pick a different $y\in Y$ for $\forall x \in X$  if we define function $f$ as $f(x)=\text{one element in Y that g(that element)=$x$}$, f is a injective function, so injective function $f:X\to Y$ exists.    But, I am not sure that my approach is right, especially on proving right to left. Please check whether my approach is right, ways to improve it,  and some other ways of proving this question.


I just installed Ubuntu on my laptop and gave my name and a password for administrator account. Later in terminal I tried to create another user. It told me that only the root user can do it but i don't know to login as root and create a new user. In red hat i know how to, because I'm a red hat user. What should i do now someone please help me. i tried the codes  2  sudo apt-get install chromium-browser 3  mkusr general use 4  crusr general use 5  mkdir mukundan 6  adduser 7  exit 8  adduser 9  root 10  sudo apt install root-system-bin 11  --fix-missing? 12  run apt-get update 13  sudo apt install root-system-bin 14  mkdir 15  su root 16  su root  17  su root 18  history   still nothing worked

I installed  (Precise Pangolin), 64 bit. Nowhere was I asked to set password for root.  I just installed  software. It was installed under the /root folder by default. Now I try do something on that folder. I tried with su to switch to root, but I don't know its password.   Should I always use sudo or get the default root password, if any?  How do I create a  for software installed inside the /root directory?


I have a voting system which allows for users to upvote and downvote on items. I am looking to improve the system because users can vote multiple times. Below you can see my code.
 Votes

 Up-Votes	 Down-Votes

 <?php   mysql_connect("localhost", "root", "PASS") or die(mysql_error());   mysql_select_db("DBNAME") or die(mysql_error());    if ( isset( $_POST['Upvote'] ) )  {   mysql_query ("UPDATE reports SET up = up + 1 WHERE reportID = $id");    } else if (isset( $_POST['Downvote'] )) {  mysql_query ("UPDATE reports SET down = down + 1 WHERE reportID = $id");  }  $data = mysql_query("SELECT * FROM reports WHERE reportID = $id") or die(mysql_error());   while($ratings = mysql_fetch_array( $data ))  {   Echo "" .$ratings['up']."	";  Echo "" .$ratings['down']."	";   }   ?>

 <form method='POST'> <input type='submit' value='up' name='Upvote' class="myButton"> <input type='submit' value='down' name='Downvote' class="myButton"> </form>    Does anybody have any suggestions which could prevent duplicate votes?  There are potentially thousands of items on my system, I am unsure as to how I can make a user be exempt from voting on particular reports  Cheers

I'm planning to add some vote up/vote down buttons to a website I run. This seems easy enough but I want to stop people voting multiple times. One solution would be to make them register before allowing them to vote but I'd prefer not to have to force them to register.   Is there are a reasonably straightforward way of doing this? Checking the IP address doesn't seem like a good solution, since it's possible that multiple users may come from the same IP address.   Cookies might be the answer, but a savvy user could delete the cookie. Any better ideas?


There is no X button and i tried to open the "Preferences" menu and when I tried to close it I somehow opened 12 of them. I somehow managed to close 1 of the menus but I did it by accident and I couldn't do it again.

I would like to close some view windows that I opened accidentally.  See the image below:    Edit: another note: I tried searching for the solution, but only found things like "Join Area", which don't seem to work in this situation.


I have an Acer Aspire One netbook which has Windows 7 starter. I have done the recent Windows updates, and says my windows 7 is all up to date. My dad has the same netbook but received the "Windows 10 icon at the bottom tray". My question is, why haven't I received the icon yet through the Windows updates? Which file contains that KB3035583?

I want to get Windows 10, but I do not see this icon in the notification area (tray):    How do I get the icon to get Windows 10?


I am trying to install skype in xubuntu 14.04 64bit from . I tried ubuntu 10.04 32bit and ubuntu 12.04(multiarch). In xubuntu 14.04 64bit for both cases it is showing broken package message. Could any one give me a solution of this problem.

Note: The legacy Skype for Linux application (v4.*) is now discontinued and was removed from Canonical’s partner repositories, so this question and its answers are obsolete. Please refer to  of our .    I am receiving the following message while I am trying to install Skype:  nidhin@ubuntu:~$ sudo apt-get update nidhin@ubuntu:~$ sudo apt-get install skype Reading package lists... Done Building dependency tree        Reading state information... Done Some packages could not be installed. This may mean that you have requested an impossible situation or if you are using the unstable distribution that some required packages have not yet been created or been moved out of Incoming. The following information may help to resolve the situation:  The following packages have unmet dependencies:  skype : Depends: skype-bin but it is not installable E: Unable to correct problems, you have held broken packages   How can I fix this?


I just asked myself. if you have:  $$x^3 -8 = 0$$ and trying to solve it, you do  $$x^3 = 8$$  well, the first real root will be $2$ because $2^3 = 8$  but it is only the first, what about second and third?


Doing reviews in low quality queue I often stumble upon weak attempts at answers that nevertheless look like salvageable.  As a rule, these are brief opinions / recommendations that could possibly become of reasonable quality if (note: if) their authors explain why they recommend it as answering the question asked.  Per my reading of , above leaves me two options: either Looks Good or Recommend Deletion. How do I choose between these?   For the sake of completeness, two other options mentioned in guidelines are Edit and Skip. Edit hardly applies, as this would essentially require reading author's mind, not something I am proficient with. Skip doesn't feel right either because I only  when I am unsure, which is not the case when I am strongly confident about my evaluation of the post content (using Skip in cases like this would simply defer decision someone else who will face same dilemma as I, not quite fair).   An example of the post like I talk about is in :     I assume some other languages now have the option of multiple return values.   Interested  can look in LQ queue history  or at  for more examples.    Note a while back, I felt rather strongly in favor of Recommend Deletion. This preference was based on my understanding of the ideas and features introduced to .  I thought, now that author can easily get to their deleted post to improve and flag for undeletion, it looks only natural to vote for removing it while it's not yet OK (heck this could even save them from a couple downvotes while their low quality content is visible and annoys readers).  But closer encounter with the way how deletion works made me wonder if above reasoning is right. When I , I realized that only recent posts are easy to find out.  When deleted post is more than 60 days old, it is quite difficult for author to discover and improve and this basically invalidates what made me believe that Recommend Deletion is so much better.  Update per : current design is such that  reaches the user, except when all reviewers select  in deletion dialog.

When reviewing low-quality posts, the help text explains:        Looks Good if nothing is wrong with this answer   Edit if you can fix all the problems with this answer   Recommend Deletion to recommend that this answer be deleted   Not Sure if you are unsure and want to skip this answer      But there is no guidance as to the thresholds. In particular, the text gives me no idea how bad a post has to be for me to be supposed to recommend deletion. For example, the most common gray area is with answers consisting of one or two lines of code. Often these can technically answer the question, but they are not very useful because they don't explain why or how it works. Should those be deleted? If not, should I really say "looks good" even though something is "obviously wrong with this answer"?  Could the help text be clarified (or at least hyperlinked to an explanation)?


How to create your own email content for all the alerts emails which are sent OOTB . I need to modify the email content of all the alerts send OOTB (The immediate emails, update email , delete email , daily summary alert email and weekly summary alert ) .  I know of creating copy of alerttemplate.xml and editing it but how to ensure all email alerts content are modified .

I have a SharePoint 2013 instance that I would like to modify the default email template.  I want to put my company's logo as a header and the company contact info as a footer on every email that is sent from SharePoint.  Is there any way to force SharePoint to use my message template?  If there is an event receiver that I can tap into, that would also work.   I am a C# developer, so if there is some custom code required, I'd actually prefer it.


A neutron star is created by the gravitational collapse of a massive star. The atoms are pushed into each other, the electrons into the protons etc. and it is held there under the existing gravitational field. What happens if you were able to remove a small amount of neutron star material and get it away from the gravitational field. Would the material stay as neutron star material or would it change to something else not that it's not subject to being crushed by gravity?

I've read on NASA's page on neutron star that one teaspoonful of that star would weigh over 20 billion tonnes on Earth. If it was somehow possible to bring it to earth would it:   Burn and disappear during Earth atmosphere entry? Assuming we have 20 billion tonnes of mass occupying the volume of a teaspoon here on Earth, would it fall through the ground under its own weight?


I have already posted my problem in stackoverflow, I am not sure if this might be problematic, and I am not sure, if the post is shown in both communities. If so I will delete.  I am trying to apply principal component analysis, to reduce the dimensions of my data. 200x146 , 200 observations(samples) with 146 features(dimensions), each observation can belong to one of three classes. What I am trying to do is to visualize the data, to see how the class centroids move after adding new samples to my data. Since it’s impossible to plot such high dimensional data, I am looking for a dimension that would represent my data in almost separate classclusters.  I know that PCA, calculates the eigenvalues of the eigenvectors, while the eigenvalues represent the variance. The higher the variance the more the data is spread out and better to visualize. The eigenvector with the highest eigenvalue is the principal component, an axis orthogonal to this component is then found by the PCA. (Did I understand the basic idea of PCA correctly?)  However I don’t understand, what information I do get when I use the matlab function pca() I get the coefficient, but what do they tell me and how to I proceed afterward?

In today's pattern recognition class my professor talked about PCA, eigenvectors and eigenvalues.   I understood the mathematics of it. If I'm asked to find eigenvalues etc. I'll do it correctly like a machine. But I didn't understand it. I didn't get the purpose of it. I didn't get the feel of it.        I strongly believe in the following quote:     You do not really understand something unless you can explain it to your grandmother. -- Albert Einstein   Well, I can't explain these concepts to a layman or grandma.   Why PCA, eigenvectors & eigenvalues? What was the need for these concepts? How would you explain these to a layman?


I've just got into keyboard shortcuts, and I found it a bit annoying that for every network site I use (Stack Overflow, Super User, Server Fault, etc.) I have to go to http://<site>.com/users/preferences/<UID> and set it on.  There are some preferences which should be per-site on that same page, e.g. the newsletter. But I think most people will want shortcut uniformity like me.

Following a global preference for , as of now, the preferences for enabling keyboard shortcuts and disabling the fixed topbar are network-wide* as well.  If you had either checked off on any site in the network, that setting has been preserved and applied to the whole network for your account already. Future changes will also apply to all* Q&A sites.  Find them in their usual spot as previously on the  pages.    * With the exception of , which will support the fixed topbar after the .


I am wondering how to perform a Fishers exact test on my data which contains two columns and three rows. One of the cells contains zero.               2012    2018 Pass          116     166 Submax         11      45 Fail            9       0   I would like to compare the data between the years 2012 and 2018. Any help would be much appreciated! I only have access to excel but if anyone else can calculate it for me that would be brilliant.

I was taught to only apply Fisher's Exact Test in contingency tables that were 2x2.  Questions:   Did Fisher himself ever envision this test to be used in tables larger than 2x2 (I am aware of the tale of him devising the test while trying to guess ) Stata allows me to use Fisher's exact test to any contingency table. Is this valid? Is it preferable to use FET when expected cell counts in a contingency table are < 5?


i need to pass a String to a method, but it doesn't work...  public static void main(String[] args) {       System.out.println("Enter a String:");     String abd = Input.readString();      long number = number(String abd);     System.out.println(number);  } public static long number(String abd){     long num= 0;      if(abd == "AAA"){         num = 100L;     }     if(abd == "BB"){         ean2 = 20L;     }      return ean2;   it prints 0 for the number...and i dont know why! i need to do this with a String...i know it would work with char...is there some way to make this work with String?

I've been using the == operator in my program to compare all my strings so far. However, I ran into a bug, changed one of them into .equals() instead, and it fixed the bug.  Is == bad? When should it and should it not be used? What's the difference?


I'm running Windows 7 Pro 64bit on a Dell Precision M4400 laptop and whenever I boot it it takes ages ( >5mins average).  This doesn't seem right as it's a fairly beasty piece of kit, It get's a 5.9 on the WEI with the lowest score being the Hard disk.  Core 2 Duo P8600 @ 2.4GHz 4GB RAM 150GB 7200RPM Hard Disk with 16MB buffer    How can I tell which part(s) of the boot sequence it taking so long so I might disable / avert the issue and improve the boot time?  The machine is part of a Windows Active Directory and I regularly use it outside the corporate network. Neither situation improves performance.  In my user profile on the AD have a login script which mounts 12 network drives using the following commands  net use I: /delete net use I: \\machine\share /persistent:no   In the startup folder on the start menu I have Sophos and Dropbox. I do have a bunch of services as I'm a developer. There are 2 versions of SQL server, Microsoft Azure developer tools and a few other bits and pieces. Ideally I'd like not to have to disable these; I'd like to see exactly how long each item is taking during boot and make educated decisions from there.

When I start my PC, it boots into Windows (Windows 7 32-bit) quite happily, I login and the main Windows screen appears. At that point, however, the system is extremely unresponsive for up to 5 minutes - if I click on Firefox to start it, nothing appears to happen for a long time, etc, etc. The mouse and Windows UI is responsive, but programs take forever to start, webpages seem to hang (or at least load extremely slowly) and so on.  I imagine that the issue is with one or more programs that run on startup, but I don't know quite how to identify which one it might be. The event log shows nothing of any obvious interest. I can't see any high CPU activity in task manager or Process Explorer, and I can't hear any high disk activity.  I'd rather understand what's happening and then work out how to address it, than have to go for a blind "switch things off and see what helps" approach, but maybe that's being optimistic :-)  I suspect disk bottlenecks or network, but I don't know how I could set something up to diagnose this (and in particular, given that I can't get programs to start in a timely manner, I'd prefer something that automatically starts and logs data for later analysis than something like Process Explorer, which always leaves me worrying that by the time it started the problem had gone away :-)  I guess my ideal would be 2 things:   Something that gave me an overall "what are the current key bottlenecks in this system" summary (ideally, which could be set to run in the background and collect data for later analysis). Some means of starting a program (say, Firefox) and have it record what was going on in terms of waits and delays in the system.   Unfortunately, I've never really found anything like either of these.  I'm not a professional systems admin - my background is database admin - so if there are "obvious" tools to look at or try, then I'd be grateful to know of them (particularly if the information they give is easy for an amateur to analyze) :-)


I face with some cases onClick or onSubmit functions needs both event and parameter. Can I do with this in react, or vanilla html tags? Or, Just do something side effect using another functions?  const CustomFC = ({}) => {   const [ id, setId] = useState("");   const [password, setPassword] = useState("");      type FormParams = {     id: string;     password: string;    }   const customClickHandler = useCallback((params: FormParams) =>    {     dispatch(params);    }, [id, password]);    const onChangeId = useCallback((id) => setId(id),[]);   const onChangePassword = useCallback((password) => setPassword(password),[]);         <Form      onClick ={customClickHandler}      onChange={{onChangeId, onChangePassword}}   /> }  // Form.tsx const Form = ({   onSubmit,   onChange, }) => {   const { onChangeId, onChangePassword } = onChange;    const handleSubmit = ( e, params ) => { // <- can this be possible?      e.preventDefault();     onSubmit(params);   }   return (     <form onSubmit={handleSubmit}>       <input ... />       <input ... />     </form>   ) }

The situation is somewhat like-  var someVar = some_other_function(); someObj.addEventListener("click", function(){     some_function(someVar); }, false);   The problem is that the value of someVar is not visible inside the listener function of the addEventListener, where it is probably being treated as a new variable.


I have Windows 7 Home Premium without internet access.  Is there a way I can download and install all of the updates that I would normally have gotten through Windows Update?  I can download from another machine and transfer using a USB drive, but I can't download anything locally (otherwise I'd use Windows Update).  The machine I can connect to the internet with is a Mac, not Windows.  So I can't use any Windows-specific software.

What options, if any, exist for offline update of Microsoft  Windows?  If a solution exists please list your experience using it.    Background:  If for any reason a computer does not have a connection to  the Internet or the connection is too slow to download  several hundreds of megabytes every so often some kind of  offline Windows Update is required.  In a multi-computer environment a lot of bandwidth (and thus in some cases money) and/or  time could also be saved if it is possible to update in an  offline manner.


Show $\{0,1\}^V\approx\wp(V)$.   The $≈$ denotes that there is a bijection between $\{0,1\}^V$ and the powerset of $V$. However, I can't understand what $\{0,1\}^V$ is if $V$ is a set?

Let $ D = 2^\mathbb{N} $, i.e., D is the set of all sets of natural numbers.   What's the meaning of this definition? Intuitively, I would suggest that $ D = \{1,2,4,...\} $ but the explanation "set of all sets" leads me to the guess that this is wrong.


I've been doing some work to prove some languages are not regular. I have previously used pumping lemma to prove by contradiction. However I am used to questions which ask to prove languages such as {a^n b^m| n ̸= m} ⊂ {a, b}* are not regular. I would use pumping lemma for these but now I have come across this language.  {w| w ∈ {a, b} * is not a palindrome}  I'm unsure how to prove it is irregular. Can it be done with pumping lemma? Or another method?

Firstly I pick a language $xyz$ where $x = \epsilon$, $y = (abb)^{k}$, $z = (bba)^{k}$ where $|y| \ge$ the number of states in the automaton representing my language. Then $xyz = (abb)^k(bba)^k$ is a palindrome.  Now I split $y$ into $uvw$, where $v \ne \epsilon$ contains a state visited more  than once. If the language is regular then $xuv^iwz$ is within the language $\forall i \ge 0$.  I choose $i = 2$, then $uv^2w = (abb)^n$ where $n > k$.  Then $xuv^2wz = (abb)^n(bba)^k$ where $n > k$, which is not a palindrome.   Firstly, is my reasoning for this particular proof correct?  I'm unsure about how to properly apply the pumping lemma to this problem. And secondly the question asks me to state a proof for palindromes in general, whereas I only attempted to prove it for a single case. Is there an example I can choose which proves the conjecture for all palindromes? I assume not, seeing as I can't think of how that could be represented using regular expressions.


See  meta post too   Currently, users with <3k reputation, while flagging to close as off topic are presented with the custom close reasons and "belongs elsewhere" close reason.  However, the removal of the default off topic and Too Localized has left behind a void that is not completely filled by custom off topic reasons. For >3k users, the freeform "" close reason works pretty well (though it ). However, <3k users do not have any valid flag options. In such cases they are force to custom flag (or pick a random close reason), which doesn't push the question into the queue.  The freeform close reason leaves a comment and creates a temporary entry in the VTC Off Topic dialog that is present only on that particular question. The close banner used is the efault off topic one (This question does not appear to be about $Topic, within the scope defined in the help center.). I don't see much scope for abuse if flaggers are allowed to use this. The most that can happen is that flaggers can  populate the dialog with nonsense close reasons will, but since it's only for that particular question I don't see much harm in this.

I really like the new option structure when flagging - I have in particular missed the "Minimal understanding" option. However, I think that one option is missing. If we look at , it has many issues. I ended up flagging it as too broad, but I would think that it is simply, well, just off-topic. So that's where I started. Hmm:  It isn't about general computing hardware/software. It certainly isn't about code problems. It could be about not demonstrating a minimal understanding of the problem - but suggesting this guy should elaborate on what he did to try to change his birthday doesn't seem right. It isn't about server and networking. It isn't really asking for recommendations. It certainly doesn't belong anywhere else on SE.  In this case, as mentioned, I flagged as too broad even though VLQ might also have been appropriate. However, if we assume that the question only contained the first sentence, and was actually well-formed, but totally off-topic such as:  How can I change my birthdate in Facebook? I looked in the FAQ and tried  but now it is locked and I cannot change it anymore.  Isn't that off-topic? Would “Minimal understanding” really be the proper selection here? As far as I can see, I can't just select “off-topic”, but have to select one of the above options. Or should those kind of posts go directly to mods every time? Edit:  of what I believe is just off-topic, but doesn't apply to any of the options given in the off-topic dialog, and which hence has to go by the mods. Edit 2:  - which I personally flagged not as OT, but as unclear. As official OT it is still a prime example where none of the generic options apply. The question (with the title included) says:  It is possible to play the DRM formatted song in Custom player like AVAudioPlayer and MPMoviePlayer [on hold] I have tried to play directly in the AVAudioPlayer or MPMoviePlayer, but the song isn't playing.  to which the SO official response is:  You may be able to get help on Super User.  Seriously? We really want him to ask this question at Super User? Edit 3: And  that I ended up flagging as unclear - although I'd say it is a prime, generic off-topic question. From Al Everetts comment below:


I purchased an iPhone 6 with FaceTime from Saudi Arabia. Can I use FaceTime while I am India because someone told me that if you purchase an iPhone in Saudi Arabia the FaceTime does not work anywhere.

I bought my iPhone 6 Plus in Dubai. I am using the phone in Sri Lanka and I cannot use the FaceTime. How can I use FaceTime while in Sri Lanka?


I'm looking for a proof of the following statement:  Let $M$ be a smooth manifold covered by two connected charts $(U,\phi) , (V,\psi)$ such that $U\cap V$ has exactly two connected components, with the following propertie: determinant of change of coorinates is positive in one and negative in the other. Then $M$ is not orientable.

Let $M$ be a manifold of dimension $n$ such that there exist two   charts $(U_a,\phi_a)$ and $(U_b,\phi_b)$ such that $U_a,U_b$ are   connected and $U_a\cap U_b\ne\emptyset$. Moreover the transition   function $\phi_{ab}$ neither preserves the orientation nor reverses the orientation. I have to show that $M$ is not orientable.   A manifold is orientable if it admits an oriented atlas, i.e. an atlas in which all the transition functions have Jacobian with positive determinant.


should we use residue and construct a contour? I can't imagine how to make it.

I'm having trouble calculating the integral  $$\int_{- \infty}^\infty \frac{\sin x}{x+i}\,dx $$  using residue calculus. I've previously encountered expressions of the form   $$\int_{- \infty}^\infty f(x) \sin x \,dx $$  where you would consider $f(z)e^{iz}$ on an appropriate contour (half circle), do away with the part of the contour that wasn't on the real axis by letting the radius go to infinity, then recover the imaginary part of the answer to get back the sine. However here, I can't replace the sine with $e^{iz}$ in my complex function because $$\operatorname{Im} \frac{e^{ix}}{x+i} \neq \frac{\sin x}{x+i}\cdots$$  How to remedy this? I'm not sure if substituting $\sin x = \frac{1}{2i}(e^{ix}-e^{-ix})$ and solving two integrals is how this problem is meant to be solved, although I'm 99% sure it would work


I am about to submit a paper in which I present a new algorithm. There are many algorithms that are named after the author in my field, but I am not sure whether the authors themselves named those after themselves, or whether others named those algorithms after the authors post-pbulication (so in other papers). Is it appropriate to name the algorithm after myself?

It is often considered a very bad idea to try to name a discovery (a law, phenomenon or an invention) after yourself.  On the other hand, there are many species names which seem to be a bastardized Latin of the discoverer's name. With gene names, I'm not sure, but I've seen many frivolous gene names, such as those inspired by cartoon characters. I wonder if you could get away with naming a gene after yourself if you wanted to.  In other cases, such as names of synthetic strains and plasmids, it is in fact preferable to use the researcher's name. Off the top of my head, I recall  - the surrounding controversy aside, given all the work she's done, what is so wrong about her wanting to name it after herself?  However, why is this so? Apparently, it can even advance to an extreme where many years after a discovery has become established and associated with Dr. Jones, when he writes a review article on applications of the Jones Effect he will still carefully avoid acknowledging this name.  Isn't it convenient to simply name something after yourself when no clever acronym exists? Isn't doing the work of the discovery enough to earn the right to name a thing? Doesn't the fact that the discovery is important enough to be published automatically imply that it's important enough to be named after oneself?


Here is my code:  String[] magic = {"stick", "hat", "witch"}; String magic1 = magic.toString(); String magic2 = Arrays.toString(magic);  System.out.println(magic1);         // this is printing a memory location System.out.println(magic2);         // this one prints: [stick, hat, witch]     What is the difference between magic1 and magic2?

In Java, arrays don't override toString(), so if you try to print one directly, you get the className + '@' + the hex of the  of the array, as defined by Object.toString():  int[] intArray = new int[] {1, 2, 3, 4, 5}; System.out.println(intArray);     // prints something like '[I@3343c8b3'   But usually, we'd actually want something more like [1, 2, 3, 4, 5]. What's the simplest way of doing that? Here are some example inputs and outputs:  // Array of primitives: int[] intArray = new int[] {1, 2, 3, 4, 5}; //output: [1, 2, 3, 4, 5]  // Array of object references: String[] strArray = new String[] {"John", "Mary", "Bob"}; //output: [John, Mary, Bob]


Because of the pandemic my work is strictly remote. I remote into my work computer via laptop. I have two monitors connected to that laptop. Sometimes when I move the ArcMap desktop program from one screen to another my attribute table is lost beyond the visual monitors and it takes a while to get it back. Online I found that unplugging and plugging my desktop from my monitors is the only thing that works. However it is only a stroke of luck that I can click on the attribute table before it disappears again. Every time this happens I loose a good 20 minutes. Does anyone have a better solution that doesn't involve randomness/luck or me going to the office to change my remote computer settings (we are not allowed in the office until May).

I am working with ArcGIS Map and using two computer screens. I use the second screen to see my attribute table clearly. But once I disconnect my main computer from the second screen and want to see the attribute table I am not able to see it. Even I restart the computer and try, it is opened somewhere. Again, when I connect my main computer with the second screen, I can see my attribute table there. It creates problem when I have to show my work to team on projector far from my second screen.


The Voyager's story from the doctor ends with this:     EMH: Computer, freeze programme. A tragic, needless death, but as you   can see, Voyager was not responsible. After Tedran was killed, Voyager   was attacked by nine Kyrian ships. My programme was disabled, most   likely when they stole my backup module. The next thing I knew, I was   standing next to this gentleman seven centuries later.   What happened after that? The  plot summary seems to be unrelated.

In Star Trek: Voyager, episode 23 of season 4 (), the episode begins with a civilization unknown until now. They claim to hold the ruins of the USS Voyager, which has otherwise contributed to the history of this civilization in a negative way, whereby Captain Janeway formed an alliance with the enemies of the people in question.  In the historical reconstructions of this event, we see many parts belonging to the ship, such as the Doctor.  This one -- having been deactivated during all these years -- still seems to be several centuries ago. The Doctor is therefore considered as the last "living" witnesses of this war.  The USS Voyager was considered a heavily armed warship with a restless and violent crew. The Doctor has done everything to set the truth about that time, and finally, all ends well, history is approved.  However, what is really going on? In the other episodes, the Doctor is always present, as well as the crew members, and the USS Voyager. At the end of the series, they all return to Earth.  What about this episode that seems to be out of the scope of the story?    I couldn't find any explanation about this episode, except that we could consider it as a separate story, but it doesn't really make sense to put an episode that has nothing to do with it in the middle of the series (even if it's very good and fits in pretty well).  I don't think this question is a duplication of , because this one is about the whole episode, as well as what really happened to the crew.


I was taught that I should use " at the start of a quote and if it carries on in subsequent paragraphs, I should put ' at the end of the first paragraph, then start the second paragraph with ' and close again with ' and so on, until the final paragraph which I close with ' ".  I cannot see any reference to this style.

When quoting on a website like Stack Exchange, we have block quotes:  like these  but if they aren't available, and I want to use "double quotation marks": "then the quote is enclosed in them like this". Now it is ok for a single paragraph, I can put "..." at the beginning and the end of the paragraph. For example, from : "The next period in the history of English was Early Modern English (1500–1700). Early Modern English was characterised by the Great Vowel Shift (1350–1700), inflectional simplification, and linguistic standardisation." That's OK. But what if I quote multiple paragraphs? Should I use "..." at the beginning and end of each paragraph separately? Example: "The next period in the history of English was Early Modern English (1500–1700). Early Modern English was characterised by the Great Vowel Shift (1350–1700), inflectional simplification, and linguistic standardisation." "The Great Vowel Shift affected the stressed long vowels of Middle English. It was a chain shift, meaning that each shift triggered a subsequent shift in the vowel system. Mid and open vowels were raised, and close vowels were broken into diphthongs." "English began to rise in prestige, relative to Norman French, during the reign of Henry V. Around 1430, the Court of Chancery in Westminster began using English in its official documents, and a new standard form of Middle English, known as Chancery Standard, developed from the dialects of London and the East Midlands" Is that the correct way? Or is there any other way to do so?


The character is the R in this picture:    I was thinking mathcal or fraktur, but it doesn't seem to be either of them. I tried the Detexify tool and What The Font, but couldn't find anything suitable.

I usually use xelatex, but I'm exploring pdflatex now. When loading specific fonts in xelatex, I can always know what characters the font has available, since I can inspect the font file in any font viewing program, or I can find out the hard way by just entering the unicode and see if the character is displayed in the output. But how does this work with a font package?  Say, for instance, that I would like to use phonetic symbols in the  font. How do I know whether the font has phonetic symbols (I assume it does), and how do I know what command I need to type in order to make them appear? My only resource is , but this only tells me what characters/commands there are available in LaTeX2e by default (depending on the font encoding), and what symbols I can find in specific packages. Phonetic symbols, for instance, are said to be in the tipa package. Does that mean I am locked to tipa if I want to use phonetic symbols with pdflatex?  Here's a pointless MWE:  \documentclass{article} \usepackage{gentium} \begin{document} Please give me some phonetic symbols here? \end{document}


My hard disk crashed and I had to reinstall Ubuntu.  I dual booted it using Wubi and I installed it in C: partition.  When I boot into Ubuntu, I can't see my partition (The partition where Windows is installed) but I can see my second partition, D:.  Do I need to mount the partition?

I wanted to ask, how can i view all my windows files on Ubuntu. I found out how to get my D drive folders but have yet not figured out how to get my C drive files. Please give me an easy way to find my files. For more information, i have installed ubuntu via wubi. Please answer my question ASAP.


I've tried systemctl disable graphical.target and didn't work. inittab says exactly "ADDING CONFIGURATION HERE WILL HAVE NO EFFECT ON YOUR SYSTEM."

I installed a graphical environment on a server and I have decided that I no longer want to run that environment at boot. How can I disable it with systemd? This is gnome desktop environment.


I have a variety of samples, each with a different standard deviation and mean. The coefficient of variation $CV$ = ${\sigma} / {\mu}$ defines the amount of variation in a population or sample around its mean.    Is it meaningful to then use $1/CV$ or some other variation on this as a weight so that, using the example above, $\mu / CV$ is the new mean for each sample?    Is this mean at all more accurate for comparing the samples?  By comparing the samples I would like to determine (eyeball) whether, adjusted for standard deviation, the means of the samples differ significantly.  I'm almost sure this is an abuse of the coefficient of variation.  Are there other less silly methods I should be looking at to adjust for differences in standard deviation among samples?

I am trying to understand the . When I try to apply it to the following two samples of data I am unable to understand how to interpret the results.  Let's say sample 1 is ${0, 5, 7, 12, 11, 17}$ and sample 2 is ${10 ,15 ,17 ,22 ,21 ,27}$. Here sample 2 $=$ sample 1 $+\ 10$ as you can see.  Both have the same standard deviation $\sigma_{2} = \sigma_{1}= 5.95539$ but $\mu_{2}=18.67$ and $\mu_{1}=8.66667$.  Now the coefficient of variation ${\sigma}/{\mu}$ will be different. For sample 2 it will be less than for sample 1. But how do I interpret that result? In terms of variance both are the same; only their means are different. So what's the use of the coefficient of variation here? It's just misleading me, or maybe I am unable to interpret the results.


Just installed windows 10 and I get these annoying shield icons whenever I create shortcuts to a desktop. What is causing it and how can I disable it for all icons?  Edit: after suggested methods still unsolved... Why does windows make it so complicated? Edit2: I FINALLY FOUND THE   P.S. If you're on Home edition, I don't think you have Local Security Policy editor available. Also if the icons remain the same just right click go to properties, change icon, select any icon and press ok.  Edit3: Found the solution but ran into bigger issue. When I try to open any windows related app it says: This app can't be opened using the built-in administrator....can't even open pictures... What a shame Windows 10

Over some of my program shortcuts and install files, there is an uac icon overlay (blue-yellow shield) and I find them really ugly. Is there any way to get rid of them please?  Edit  I closed UAC to see if overlays go away or not. Now it's open. But maybe there is a way to remove them without closing the UAC like removing shortcut arrows in this question:


Let $( \Omega, F, P)$ be a probability space.  Let $X$ be a stochastic process defined on such probability space whose sample paths are RCLL (right continuous on $[0, \infty)$ with finite left hand limits on $(0, \infty)$. Let $A$ be the event that $X$ is continuous on $[0,t_0)$.   I am tasked in showing that $A \in F^X_{t_0}$, where $F^X_{t_0}:= \sigma(X_s ; 0 \le s \le t) = \{ \{ X_s \in B \}\subset \Omega : B \in \mathcal{B}(\Bbb{R}),  0 \le s \le t  \}$   Some may recognize this exercise as one of the first from Brownian Motion and Stochastic Calculus by Karatzas and Shreve, I am in fact trying to self study this book through august.  My problem here is that I can't figure out exactly what $A$ represents, I know that for a fixed $w \in \Omega$ I have that  $X_s(w)$ is RCLL but I can't figure out how to start.

I just started to working through Karatzas and Shreve "Brownian Motion and Stochastic Calculus". Solving an exercise there's some questions around. I want to prove.     Let $X$ be a stochastic process, every sample path of which is RCLL. Let $A$ be the event that $X$ is continuous on $[0,t_0)$. Show that $A\in \mathcal{F}_{t_0}^X$, where the latter is defined as, $\mathcal{F}_{t_0}^X:=\sigma{(\{X_s;0\le s\le t_0\})}$   What I did (sketch):  Write $A$ as,   $$ A=\{\omega \in \Omega; \lim_{s\uparrow t}X_s(\omega)=\lim_{s\downarrow t}X_s(\omega)\}$$  for $t\in [0,t_0)$. Since the Limit of a sequence of measurable functions is measurable, this is in $\mathcal{F}_{t_0}^X$. For more details see the answer of Byron Schmuland below.   Now here's the part which is unclear. There's a second claim, very similar to the first one:       Let $X$ be a stochastic process whose sample paths are RCLL a.s. Let $A$ be the event that $X$ is continuous on $[0,t_0)$. Show that $A$ can fail to be in $\mathcal{F}_{t_0}^X$. But if $\{\mathcal{F_t;t\ge 0}\}$ is a filtration satisfying $\mathcal{F}^X_t\subset\mathcal{F}_t,t\ge 0$ and $\mathcal{F}_{t_0}$   is complete under P, then $A \in \mathcal{F}_{t_0}$.   There's a sample solution to this second question. But what I don't get is the difference between the two questions. What exactly is the difference? As mentioned in my comment after Byron Schmulands answer I think this is more a linguistic problem.    cheers  math


I want to make simply count the numbers automatically when mouse left click holding. I can make it on keyboard but cant on mouse. import keyboard  a = 0 while True:     try:         if keyboard.is_pressed('q'):             a += 1;             print(a)     except:         break     When I press and hold it, it writes numbers on the screen by increasing it. Just i want "mouse click then holding" version of this code. from pynput.mouse import Listener def on_move(x, y):     print("mouse moved") def on_click(x, y, button, pressed):     if pressed:     print("mouse clicked") def on_scroll(x, y, dx, dy):     print("mouse scrolled") with Listener(on_move=on_move, on_click=on_click, on_scroll=on_scroll) as listener:     listener.join()  The above codes running perfect but just i need mouse click holding event. Or is there something like un_click event?

How can I detect mouse clicks regardless of the window the mouse is in?  Perferabliy in python, but if someone can explain it in any langauge I might be able to figure it out.  I found this on microsoft's site:   But I don't see how I can detect or pick up the notifications listed.  Tried using pygame's pygame.mouse.get_pos() function as follows:  import pygame pygame.init() while True:     print pygame.mouse.get_pos()   This just returns 0,0. I'm not familiar with pygame, is something missing?  In anycase I'd prefer a method without the need to install a 3rd party module. (other than pywin32  )


I am using an android x86 project named prime os version 0.4.5beta and I'm trying to find the data usage settings but I can't find it, I have also used the other x86 project like lineage, bliss, and the stock android x86 but none of them show the option in the settings app and I would like to be able to control how my internet will consumed by apps. If somebody has a solution please tell me what to do to make the option available.

How to turn off data after a certain amount  Aim: To make my data turn off after it reaches a predefined amount of data to use. For example, I am using my portable hotspot to my computer with my phone. After the data used on my phone goes over 100 Mbs of used data the phones then turns the data switch off.   Problems: Since my phone is android gingerbread (2.3.6) I don't have the built in data counter that is available in the newer versions of android.  Is this possible with tasker or a play store app?  Any help would be appreciated     To anyone wanting an a step-by-step Instructions just leave a comment and I will post a link to a word document, pdf and a txt file (I would have to write them up first)