[BioC] find and replace, average of 4 rows

[Dr Gyorffy Balazs]

Hi all,

I am a newbie, so maybe my questions are very simple:

Question 1. I have negative values after background
substraction in a DNA chip data, and I want to discard
these values.

The data looks like:
Gene1   0.3  0.2  0.6
Gene2   0.4  -0.1  1.2
Gene3   1.4  0.4  1.3

And I want:

Gene1   0.3  0.2  0.6
Gene2   0.4  NA  1.2
Gene3   1.4  0.4  1.3

Question 2. I have 4 spot for each gene:

Gene1_spot1 0.2  0.3
Gene1_spot2 0.3  0.5
Gene1_spot3 0.4  0.5
Gene1_spot4 0.5  0.2
Gene2_spot1 1.3  2.3

How can I calculate the mean of these spots? (mean of spots
1-4 for sample 1, then mean of spots 5-8 etc)

Thanks
Balazs Gyorffy


	
	
		
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