Implement sparse * diagonal and diagonal * sparse operations, double-prec only. Date: Sun, 8 Mar 2009 16:28:18 -0400 These preserve sparsity, so eye(5) * sprand (5, 5, .2) is *sparse* and not dense. This may affect people who use multiplication by eye() rather than full(). The liboctave routines do *not* check if arguments are scalars in disguise. There is a type problem with checking at that level. I suspect we want diag * "sparse scalar" to stay diagonal, but we have to return a sparse matrix at the liboctave. Rather than worrying about that in liboctave, we cope with it when binding to Octave and return the correct higher-level type. The implementation is in Sparse-diag-op-defs.h rather than Sparse-op-defs.h to limit recompilation. And the implementations are templates rather than macros to produce better compiler errors and debugging information.

Octave works best with gnuplot 4.2, which is available from
http://www.gnuplot.info.

Octave now sends data over the same pipe that is used to send commands
to gnuplot.  While this avoids the problem of cluttering /tmp with
data files, it is no longer possible to use the mouse to zoom in on
plots.  This is a limitation of gnuplot, which is unable to zoom when
the data it plots is not stored in a file.  Some work has been done to
fix this problem in newer versions of gnuplot (> 4.2.2).  See for
example, this thread

  http://www.nabble.com/zooming-of-inline-data-tf4357017.html#a12416496

on the gnuplot development list.


John W. Eaton
jwe@bevo.che.wisc.edu
University of Wisconsin-Madison
Department of Chemical Engineering

Last updated: Wed, 31 Oct 2007 16:28:39 EDT