Changeset 4144 for trunk/psLib/src/dataManip/psMatrix.c

Timestamp:

Jun 7, 2005, 4:38:02 PM (21 years ago)

Author:

desonia

Message:

added notes, removed references to non-existant code.

File:

• trunk/psLib/src/dataManip/psMatrix.c (modified) (4 diffs)

trunk/psLib/src/dataManip/psMatrix.c

@@ -21 +21 @@
  *  @author Robert DeSonia, MHPCC
  *
- *  @version $Revision: 1.29 $ $Name: not supported by cvs2svn $
- *  @date $Date: 2005-05-25 20:26:55 $
+ *  @version $Revision: 1.30 $ $Name: not supported by cvs2svn $
+ *  @date $Date: 2005-06-08 02:38:02 $
  *
  *  Copyright 2004-2005 Maui High Performance Computing Center, University of Hawaii
@@ -195 +195 @@
     outImage = psImageRecycle(outImage, inImage->numCols, inImage->numRows, inImage->type.type);
 
-    PS_CHECK_SQUARE(inImage, psMatrixLUD_EXIT);
+    PS_CHECK_SQUARE(inImage, psMatrixLUD_EXIT); // gsl_linalg_LU_decomp would fail on non-square input.
     PS_CHECK_SQUARE(outImage, psMatrixLUD_EXIT);
 
@@ -223 +223 @@
 
     // Calculate LU decomposition
-    gsl_linalg_LU_decomp(lu, &perm, &signum);
+    gsl_linalg_LU_decomp(lu, &perm, &signum); // N.B., uses Gaussian Elimination with partial pivoting.
 
     // Copy GSL matrix data to psImage data
@@ -412 +412 @@
     // Perform multiplication
     gsl_linalg_matmult(m1, m2, m3);
+    // N.B., gsl_blas_sgemm/dgemm could have been used instead, e.g.,
+    // gsl_blas_dgemm(CblasNoTrans, CblasNoTrans, 1.0, m1, m2, m3)
 
     // Copy GSL matrix data to psImage data