From bug-octave-request at che dot utexas dot edu  Tue May 17 16:48:58 1994
Subject: Re: Matrix with negative # of column or row 
From: John Eaton <jwe at che dot utexas dot edu>
To: "G.Beyerle" <gbeyerle at AWI-Potsdam dot DE>
cc: bug-octave at che dot utexas dot edu
Date: Tue, 17 May 94 16:48:47 EDT

"G.Beyerle" <gbeyerle at AWI-Potsdam dot DE> wrote:

: the following (admittedly non-sense) statements lead to
: matrices with negative number of rows or columns.
: 
: octave:1> x=[1 2 3]
: octave:2> x([2 2 2 2 2])=[]
: octave:3> size(x)
: ans =
:  
:    1  -2
:
: And furthermore:
:
: octave:1> x=[1 2 3]
: octave:2> x([2*ones(1,1000)])=[]
: error: caught SIGSEGV -- stopping myself...
: Segmentation fault

Here's a patch that should fix these problems.  Thanks,

jwe


--- src/tc-assign.cc.orig	1994/04/09 23:01:28
+++ src/tc-assign.cc	1994/05/17 20:14:06
 at @ -1853,7 +1853,7 @@
 void
 tree_constant_rep::delete_rows (idx_vector& iv)
 {
-  iv.sort ();
+  iv.sort_uniq ();
   int num_to_delete = iv.length ();
 
   if (type_tag == matrix_constant)
 at @ -2023,7 +2023,7 @@
 void
 tree_constant_rep::delete_columns (idx_vector& jv)
 {
-  jv.sort ();
+  jv.sort_uniq ();
   int num_to_delete = jv.length ();
 
   if (type_tag == matrix_constant)
--- src/idx-vector.h.orig	1994/03/09 21:19:44
+++ src/idx-vector.h	1994/05/17 20:14:35
 at @ -62,6 +62,7 @@
   int ones_count (void) const;
 
   void sort (void);
+  void sort_uniq (void);
 
 // i/o
 
--- src/idx-vector.cc.orig	1993/11/30 20:24:36
+++ src/idx-vector.cc	1994/05/17 21:39:16
 at @ -1,7 +1,7 @@
 // Very simple integer vectors for indexing              -*- C++ -*-
 /*
 
-Copyright (C) 1992, 1993 John W. Eaton
+Copyright (C) 1992, 1993, 1994 John W. Eaton
 
 This file is part of Octave.
 
 at @ -287,6 +287,30 @@
 {
   qsort ((void *) data, len, sizeof (int),
 	 (int (*)(void*, void*)) intcmp); 
+}
+
+void
+idx_vector::sort_uniq (void)
+{
+  if (len > 0)
+    {
+      sort ();
+
+      int *new_data = new int [len];
+      new_data[0] = data[0];
+      int k = 0;
+      for (int i = 1; i < len; i++)
+	{
+	  if (data[i] != new_data[k])
+	    {
+	      k++;
+	      new_data[k] = data[i];
+	    }
+	}
+      delete [] data;
+      len = k+1;
+      data = new_data;
+    }
 }
 
 ostream&