It's PI_Time
Introduction: It's PI_Time
PI its all around in every aspect of life and invariably goes un-noticed like most things until you have a requirement to take note.
But what is PI, it's the 16th letter of the Greek alphabet and expressed as an irrational number that's a decimal infinite.
Meaning it's a real number that cannot be expressed as a simple fraction and after the decimal point the digits are infinite.
For example
PI to 8 decimal digits: 3.14159265 which for most general purposes should be more than enough.
But if you feel the need for greater precision how about 5 trillion digits.
Here is just one source of PI to many digits. Digits of Pi - Up to 1 Million Digits (angio.net)
* No association or affiliation and you may have your own favourite. *
Take the circumference of any circle and divide it by its diameter and you have your piece of Pi(E).
π = Circumference / Diameter.
Supplies
Excel for VBA
This Instructable assumes you have access to Developer in Excel and can create a Module in which to copy the main body of the code and the Workbook_Open.
Details can be found here: spreadsheeto.com * No association or affiliation and you may have your own favourite. *
Step 1: Round in Circles
PI is all around us and in no more an obvious use than the passage of time represented by a analogue clock.
After all its a circle that's divided in to 12 periods of time representing the hours.
PI is equal to 180 degrees, therefore 2PI =360 degrees.
360 degrees/12 = 30 degrees per hour = hours*(1/12)*(2*PI) = hours*(1/6)*PI
But making use of PI what more fitting a way to represent time than with a PI chart.
The PI(E) chart will be created in Excel using VBA and display and update the clock in real time.
Step 2: Pie Hands
We can represent time in intervals of PI on a chart but how will the time interval be presented using a pie chart.
In this case the start & end point will be reference as 12*(PI/6),.
Meaning that each interval of time will be indicated by an ever decreasing pie as each slice of time is removed.
Example - Hour hand of the PI clock representing 1 o'clock.
The same methodology will be applied for the minutes and the seconds, meaning that the clock will require 3 pie charts.
Step 3: Pie Time
Including the 3 pie charts on the same axis gives the following:
Time = 1 hour, 20 minutes & 45 seconds.
The same diameter circumferences overlap making it difficult to determine the time when pie edges overlap.
Therefore, each pie will have a different diameter in a similar manner to a conventional clock.
Step 4: Pie Filling
By filling each pie in a different colour we can now differentiate the hours, minutes and seconds and the overlaps are clearer.
It was decided to make the seconds the larger pie, next the minutes and the smallest the hours.
Step 5: Baked Pie
The final modifications are a title, replacing the PI identities with whole numbers (substituting with roman numerals), and automating the process such that it updates in real time.
Step 6: The Code
TimeFormat
The heart of the PI_Time clock is this function.
This function reads Now(), which contains a string with the date and time.
From this is extracted the time section this is then split into the 3 main parts of Hours, Minutes and Seconds.
This data is then formatted to enable creation of the 3 pie charts (which in reality are 3 series in a Radar/Spider chart with a fill).
The position in the pie stack is determined by the order in which the data series is presented this being Seconds, Minutes and Hours.
The chart data elements are divided into 24 cells per time type for circumference. Greater resolution can be achieved by having more cells per time type and therefore more increments on the circumference. 371
But as its an analogue clock its not deemed a significant issue having less resolution. If absolute values of time are needed than its probably better to have a digital clock. Although digital time can be displayed on the same chart if required.
The time value is converted into a linear end point were all intermediate values except the first value are all set to 0. All the points between the first and end point represent the part of the pie which is removed as time progresses the end point is extended until all the values except the first are set to zero. At which point the pie is no more.
Each chart data element per time type has a different maximum value to which all the elements are set which defines the diameter of the associated pie. 915