From bug-octave-request at bevo dot che dot wisc dot edu Tue Dec  9 23:52:41 2003
Subject: Incorrect dimensions of subarrays of ND Arrays
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: Quentin Spencer <qspencer at ieee dot org>
Cc: bug-octave at bevo dot che dot wisc dot edu
Date: Tue, 9 Dec 2003 23:52:21 -0600

On 29-Nov-2003, Quentin Spencer <qspencer at ieee dot org> wrote:

| First, I want to thank all of those who have worked to make Nd arrays 
| possible. I am testing some MATLAB scripts that use ND arrays in octave 
| and got the following problem:
| 
|  > a=ones(4,5,6);
|  > size(a)
| ans =
| 
|         4        5        6
| 
|  > size(a(1:2,:,4))
| ans =
| 
|         2        5        1
| 
| In MATLAB, this returns a matrix of dimension [2,5]. The fact that this 
| returns a 3 dimensional array broke an assignment operation in one of my 
| scripts where a 2-dimensional "slice" of a 3-dimensional array was 
| assigned to a part of a 2-dimensional array.

Please try the following patch.

Thanks,

jwe

liboctave/ChangeLog:

2003-12-09  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>

	* dim-vector.h (dim_vector::chop_trailing_singleton_dims,
	dim_vector::dim_vector_rep::chop_trailing_singleton_dims):
	New functions.
	* Array.cc (ArrayN<T>::indexN): Use it.
	(ArrayN<T>::index (Array<idx_vector>&, int, const T&)): Likewise.


Index: liboctave/dim-vector.h
===================================================================
RCS file: /usr/local/cvsroot/octave/liboctave/dim-vector.h,v
retrieving revision 1.9
diff -u -r1.9 dim-vector.h
--- liboctave/dim-vector.h	24 Nov 2003 21:24:37 -0000	1.9
+++ liboctave/dim-vector.h	10 Dec 2003 05:50:55 -0000
 at @ -111,6 +111,17 @@
       return dims[i];
     }
 
+    void chop_trailing_singletons (void)
+    {
+      for (int i = ndims - 1; i > 1; i--)
+	{
+	  if (dims[i] == 1)
+	    ndims--;
+	  else
+	    break;
+	}
+    }
+
   private:
 
     // No assignment!
 at @ -200,7 +211,6 @@
       }
   }
 
-
   std::string str (char sep = 'x') const
   {
     OSSTREAM buf;
 at @ -287,6 +297,12 @@
 
     return retval;
   }
+
+  void chop_trailing_singletons (void)
+  {
+    make_unique ();
+    rep->chop_trailing_singletons ();
+  }
 };
 
 static inline bool
Index: liboctave/Array.cc
===================================================================
RCS file: /usr/local/cvsroot/octave/liboctave/Array.cc,v
retrieving revision 1.78
diff -u -r1.78 Array.cc
--- liboctave/Array.cc	25 Nov 2003 05:41:35 -0000	1.78
+++ liboctave/Array.cc	10 Dec 2003 05:50:52 -0000
 at @ -1859,6 +1859,7 @@
 	  else
 	    {
 	      dim_vector new_dims;
+
 	      new_dims.resize (n_dims);
 
 	      for (int i = 0; i < n_dims; i++)
 at @ -1867,6 +1868,8 @@
 		    new_dims(i) = 1;
 		}
 
+	      new_dims.chop_trailing_singletons ();
+
 	      retval = Array<T> (new_dims);
 	    }
 	}
 at @ -1885,6 +1888,8 @@
 		    new_dims(i) = 1;
 	        }
 
+	      new_dims.chop_trailing_singletons ();
+
 	      retval = Array<T> (tmp, new_dims);
 	    }
 	  else
 at @ -1917,6 +1922,8 @@
 	      result_dims(1) = (ntot > 0 ? 1 : 0);
 	    }
 
+	  result_dims.chop_trailing_singletons ();
+
 	  retval.resize (result_dims);
 
 	  int n = number_of_elements (result_dims);
 at @ -2018,6 +2025,8 @@
 
   dim_vector frozen_lengths = short_freeze (ra_idx, dimensions, resize_ok);
 
+  frozen_lengths.chop_trailing_singletons ();
+
   if (frozen_lengths.length () <= n_dims)
     {
       if (all_ok (ra_idx))
Index: src/ChangeLog
===================================================================
RCS file: /usr/local/cvsroot/octave/src/ChangeLog,v
retrieving revision 1.894
diff -u -r1.894 ChangeLog
--- src/ChangeLog	28 Nov 2003 02:50:12 -0000	1.894
+++ src/ChangeLog	10 Dec 2003 05:51:04 -0000
 at @ -1,3 +1,11 @@
+2003-12-09  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>
+
+	* OPERATORS/op-cell.cc: Allow transpose for cell arrays.
+	* OPERATORS/op-m-m.cc, OPERATORS/op-cm-cm.cc,
+	OPERATORS/op-bm-bm.cc, OPERATORS/op-streamoff.cc,
+	OPERATORS/op-str-str.cc: Improve error message for attempt to
+	transpose N-d object.
+
 2003-11-27  John W. Eaton  <jwe at bevo dot che dot wisc dot edu>
 
 	* pt-arg-list.cc (F__end__): Handle N-d objects.



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