subsetting a matrix/array in R

January 7, 2010

(This article was first published on simon jackman's blog » R, and kindly contributed to R-bloggers)

From the R-devel svn log. Nice addition…

r50896 | falcon | 2010-01-05 12:05:31 -0800 (Tue, 05 Jan 2010) | 7 lines
Changed paths:
M /trunk/NEWS
M /trunk/src/include/Defn.h
M /trunk/src/library/base/man/Extract.Rd
M /trunk/src/main/subassign.c
M /trunk/src/main/subscript.c
M /trunk/src/main/subset.c
M /trunk/tests/Makefile.common
A /trunk/tests/array-subset.R

Allow n-dim arrays to be subsetted by an n-column character matrix

The character matrix is converted to the corresponding integer matrix
by matching against the dimnames of the array. NA values in any row
of the character matrix are propagated to the result. Unmatched
values result in a subscript out of bounds error. Empty string “” is
not allowed to match and therefore always results in an error.

I wonder about an option controlling the behavior of non-matches?

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