Re: FYI: sparse indexed assignment rewritten

[David Bateman]

Jaroslav Hajek wrote:
> On Fri, Apr 16, 2010 at 1:02 PM, David Bateman <address@hidden> wrote:
>   
> > Jaroslav Hajek wrote:
> >     
> > > On Wed, Apr 14, 2010 at 3:44 PM, John W. Eaton <address@hidden> wrote:
> > >
> > >       
> > > > On 13-Apr-2010, Jaroslav Hajek wrote
> > > >    | 3. simple grep query shows that the interpreter uses nzmax at
> > > > | suspiciously many places. I bet some of those usages are wrong and
> > > > | should be nnz, but it requires individual approach. So get ready for
> > > > | mysterious crashes, just in case.
> > > >
> > > > I guess we need to look at all nzmax uses and decide whether they
> > > > should be nnz instead.  Are there any simple rules for when nzmax is
> > > > required?
> > > >
> > > >         
> > > nzmax is now (as it should have always been) just the amount of space
> > > allocated for nz elements. So probably anything that merely reads the
> > > matrix wants to use nnz(). An exception is conversion (conversions
> > > should preserve nzmax because of spalloc), but I think I already
> > > handled that.
> > >
> > >
> > >       
> > I started to look at this and have a question. For the octave file formats
> > do we want to save the sparse matrix in a way that preserves the values of
> > nzmax if it is different than nnz? If we do, then we need to change the
> > format as only one of these values is currently saved. A similar issue
> > exists for the matlab file format.. They save the value of nzmax in the tag
> > and nnz can be derived from the element length (given in bytes). However as
> > I no longer have access to matlab I'm unsure if matlab uses this to save the
> > value of nzmax or not.. What does
> >
> > s = spalloc (10,10,10);
> > save -v6 f.mat s
> > clear all
> > load f.mat
> > nzmax(s)
> >
> > give in a recent version of matlab?
> >
> > Cheers
> > David
> >
> >     
>
> I don't see much reason to save nzmax > nnz. nzmax is tightly related
> to memory, not to the actual value of the matrix. I suppose that when
> saving, you want to save only as much data as needed. I'd say let's
> save just nnz and the valid data, which is a non-disturbing change. If
> anyone can bring forward arguments why saving also nzmax is desired,
> it can be discussed and possibly changed.
>
> regards
>
>   
Ok, then consider the attached changeset which has the following properties

- nzmax is preserved for transfers between oct and mex APIs
- nzmax is lost when saving to octave file formats
- libraries like CHOLMOD, etc use the variable name nzmax internally for 
nnz and these usages have been left
- the Fsparse now respects the nzmax argument when given
- ls-mat5.cc not yet treated as I need to know what matlab gives for

s = spalloc (10,10,10);
save -v6 f.mat s
clear all
load f.mat
nzmax(s)

- Other uses of nzmax changed to nnz

So only loading and saving of matlab files should now cause problems 
when nzmax doesn't equal nnz. The remaining uses of nzmax except in 
ls-mat5.cc should now be correct.

Cheers
David

diff --git a/scripts/plot/__go_draw_axes__.m b/scripts/plot/__go_draw_axes__.m
--- a/scripts/plot/__go_draw_axes__.m
+++ b/scripts/plot/__go_draw_axes__.m
@@ -23,9 +23,9 @@
 
 ## Author: jwe
 
-function __go_draw_axes__ (h, plot_stream, enhanced, mono, implicit_margin)
+function __go_draw_axes__ (h, plot_stream, enhanced, mono, implicit_margin, 
bg_is_set)
 
-  if (nargin >= 4 && nargin <= 5)
+  if (nargin >= 4 && nargin <= 6)
 
     showhiddenhandles = get (0, "showhiddenhandles");
     unwind_protect
@@ -1551,10 +1551,18 @@
        elseif (is_image_data (i))
          if (! is_image_data (i-1))
            fputs (plot_stream, "; ");
+            if (bg_is_set)      
+              fputs (plot_stream, "unset obj 1; \\\n");
+              bg_is_set = false;
+            endif
          endif
           fprintf (plot_stream, "%s \"-\" %s %s %s \\\n", plot_cmd,
                   usingclause{i}, titlespec{i}, withclause{i});
        elseif (is_image_data (i-1))
+          if (bg_is_set)      
+            fputs (plot_stream, "unset obj 1; \\\n");
+              bg_is_set = false;
+            endif
          fprintf (plot_stream, "%s \"-\" binary format='%%float64' %s %s %s 
\\\n", plot_cmd,
                   usingclause{i}, titlespec{i}, withclause{i});
        else
@@ -1593,6 +1601,11 @@
     if (view_map)
       fputs (plot_stream, "unset view;\n");
     endif
+    
+    if (bg_is_set)      
+      fputs (plot_stream, "unset obj 1;\n");
+      bg_is_set = false;
+    endif
 
     fflush (plot_stream);
 
diff --git a/scripts/plot/__go_draw_figure__.m 
b/scripts/plot/__go_draw_figure__.m
--- a/scripts/plot/__go_draw_figure__.m
+++ b/scripts/plot/__go_draw_figure__.m
@@ -97,21 +97,18 @@
                     axes_position_on_page = orig_axes_position .* 
paper_position([3, 4, 3 ,4]);
                     axes_position_on_page(1:2) = axes_position_on_page(1:2) +  
paper_position(1:2);
                     set (kids(i), "position", axes_position_on_page);
-                    __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, 
implicit_margin);
+                    __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, 
implicit_margin, bg_is_set);
                   else
                     ## Return axes "units" and "position" back to their 
original values.
-                    __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, 
implicit_margin);
+                    __go_draw_axes__ (kids(i), plot_stream, enhanced, mono, 
implicit_margin, bg_is_set);
                   endif
                   unwind_protect_cleanup
                   set (kids(i), "units", orig_axes_units);
                   set (kids(i), "position", orig_axes_position);
+                  bg_is_set = false;
                   if (fg_is_set)
                     fputs (plot_stream, "unset obj 2\n");
                   endif
-                  if (bg_is_set)
-                    fputs (plot_stream, "unset obj 1\n");
-                    bg_is_set = false;
-                  endif
                 end_unwind_protect
               otherwise
                 error ("__go_draw_figure__: unknown object class, %s", type);