On Aug 10, 2011, at 8:23 PM, Andra Isan wrote:
Hi All,
I would like to create a matrix in R but I dont know the size of my
matrix. I only know the size of the columns but not the size of the
rows. So, is there any way to create a dynamic matrix of size NULL
by n_cols? and then add to that matrix?
I know for a vector, I can do this: x= NULL but is there any way to
do the same for a matrix as well?
No. You cannot make an R matrix without knowing the number of rows. By
definition an R matix has two integer dimensions. Alternatives: You
can rbind to an existing matrix, or you can make a larger than
necessary matrix filled with NA's and then fill and later extract a
subset of the rows.
--
David Winsemius, MD
West Hartford, CT
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