Hello Folks. This must be a silly question with a (not) obvious (to me)
answer.
Consider this:
tmp - matrix(1:200, nrow = 20)
vec - 300:309
tmp[9,] - vec # replacing one row works fine
p - c(3, 11, 17)
tmp[p,] - vec
# replacing multple rows pastes the values down a column and recycles vec.
vec is being recycled column wise, so you can repeat each element the
required number of times:
tmp[p,] - rep(vec, each = length(p))
There's many ways to achieve this though, so it depends on what other
variations you might want to deal with.
Cheers, Mike.
On Mon, Nov 29, 2010 at 2:53 PM,
Hi Bryan,
The reason vec gets recycled is that you are replacing more values
than vec has. Just look at:
tmp[p, ]
this is 3 x 10 matrix, which you are trying to replace with a vector
of length 10. If you want the replacement to occur without any
recycling, you'll need to make vec be a matrix
On 2010-11-28 19:53, Bryan Hanson wrote:
Hello Folks. This must be a silly question with a (not) obvious (to me)
answer.
Consider this:
tmp- matrix(1:200, nrow = 20)
vec- 300:309
tmp[9,]- vec # replacing one row works fine
p- c(3, 11, 17)
tmp[p,]- vec
# replacing multple rows pastes the
Thanks to Michael, Josh and Jorge - Problem fixed. Michael's suggestion was
what I needed, but I wouldn't have ever conceptualized it that way, and
Jorge showed me how simple the function could be (at this hour, I was
imagining it would be more work). Thanks guys. Bryan
On 11/28/10 11:03 PM,
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