[R] sparse data frame (crsp?)

ivo_welch-rstat8303@mailblocks.com ivo_welch-rstat8303 at mailblocks.com
Tue Jul 26 03:49:11 CEST 2005

thank you for the hints.  a matrix is and it isn't the right tool for 
the job.  it is really a data frame, not a matrix.  the columns have 
meanings.  actually, a more general data frame would make a nice 
feature for the future---as if the folks doing the R development did 
not have enough to do ;-).  one particular kind of sparse data set 
implementation would make sense, in which either rows or columns are 
assumed to be contiguous, and an internal R parameter determines the 
start and end.  I bet there are many data sets that take the form of 
data that is available for a a consecutive set of columns only.  the 
data structure implementation of such a data frame may not be too 
difficult, either.


ivo welch

-----Original Message-----
From: roger at ysidro.econ.uiuc.edu
To: ivo_welch-rstat8303 at mailblocks.com
Cc: r-help at stat.math.ethz.ch
Sent: Mon, 25 Jul 2005 03:58:09 -0500 (CDT)
Subject: Re: [R] sparse data frame (crsp?)

You could try reading it in a chunk at a time and making a sparse
matrix with SparseM, unless you really need some functionality
of dataframes.

R Koenker

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