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extract cells by columns/rows from matrix

2 messages · Nicolas Gutierrez, Jannis

#
hi All,

I have a matrix Ufi (x by y)

   1  2  3  4  5
1 0  0  0  0  3
2 0  0  0  9  0
3 0  2  0  0  3
4 0  0  1  0  0
5 0  1  0  0  0

And I need the x and y "coordinates" of those cells with maximum values:

First:

x=4; y=2  (Value=9)

Second:

x=5; y=3  (value=3)

Any help?
THANKS!

Nic
#
which(data==max(data),arr.ind=TRUE)

gives you the indices of the largest element.

which(data==data[order(data)[2]],arr.ind=TRUE)

the indices of the second largest.

Best
Jannis
On 04/14/2011 10:23 PM, Nicolas Gutierrez wrote: