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Given a tab separated data file (or another separator), how would you compute the mean of a column?

Too bad that there are no simple binaries that performs simple mathematical operations over those kind of files.

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up vote 7 down vote accepted
awk -F'\t' '{ sum += $1 } END { print sum / NR }'

Here $1 is the first \tab-separated column.

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If you have R installed you can also use:

Rscript -e "(mean(read.table(\"file.tab\")))"

You can also change the function (mean) to other statistical functions, say:

Rscript -e "(mean(read.table(\"file.tab\")))"
Rscript -e "(sd(read.table(\"file.tab\")))"
Rscript -e "(summary(read.table(\"file.tab\")))"

If you want to specify the column, say, use column 3, then you use the notation [,3]

Rscript -e "(sum(read.table(\"file\")[,3]))"

Enjoy!

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