<p>Hello friends, please help me</p>

<p>i entered these codes, but whenever i use the output as input to geworkbench, it says that&quot; <strong>could not parse line #1, line should have 12 columns but has 13 columns, which need manually add a tab at the beggining of the header to make it a valid RMA format</strong>&quot;</p>

<pre>
library(affy)

&gt; data &lt;- ReadAffy()
&gt; exp &lt;- rma(data)

Background correcting
Normalizing
Calculating Expression
&gt; control &lt;- grep(&quot;AFFX&quot;,rownames(exp))
&gt; exp &lt;- exp[-control,]
&gt; e &lt;- exprs(exp)
&gt; e &lt;- apply(e,1,function(x) x-median(x))
&gt; e.scaled &lt;- t(scale(t(e),center=FALSE))
&gt; write.exprs(exp, file=&quot;output.txt&quot;, sep=&quot;\t&quot;)</pre>

<p><strong>where i did wrong please??</strong></p>

Change:

    write.exprs(exp, file="output.txt", sep="\t")

to:

    write.exprs(exp, file="output.txt", sep="\t", row.names=FALSE)