[R] filtering lines in a table

[Alexandre Fayolle]

Hello,

I realize this is probably a dumb question, but I think there must be an
easy way to do this with R and I was not able to find it in the doc. 

I have a table (read from a file with read.table), with two factor
columns, table$A and table$B, and a numerical column, table$X. I wish to
make a boxplot of  (table$X ~ table$A) for a given value of B. Is there
a way to express this with a formula, or is it necessary to manually
extract the right lines in the table? In that case, what is the best way
to do so?

Thanks for your help


Alexandre "R newby" Fayolle

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