Changeset 1566 in Sophya for trunk/SophyaExt

Timestamp:

Jul 5, 2001, 5:45:50 PM (24 years ago)

Author:

ansari

Message:

Ajout commentaires-documentation ds LapackServer::LeastSquareSolve() - Reza 5/7/2001

Location:

trunk/SophyaExt/LinAlg

Files:

• intflapack.cc (modified) (2 diffs)
• intflapack.h (modified) (1 diff)

trunk/SophyaExt/LinAlg/intflapack.cc

@@ -154 +154 @@
 }
 
+//! Interface to Lapack least squares solver driver s/d/c/zgels().
+/*! Solves the linear least squares problem defined by an m-by-n matrix 
+  \b a and an m element vector \b b .
+  A solution \b x to the overdetermined system of linear equations
+  b = a * x is computed, minimizing the norm of b-a*x. 
+  Underdetermined systems (m<n) are not yet handled.
+  Inout arrays should have FortranMemory mapping (column packed).
+  \param a : input matrix, overwritten on output
+  \param b : input-output, input vector b, contains x on exit.
+  \return : return code from lapack driver _gels()
+  \warning : b is not resized.
+ */
+/*
+  $CHECK$ - A faire - cas m<n 
+       If the linear system is underdetermined, the minimum norm 
+       solution is computed. 
+*/
+
 template <class T>
 int LapackServer<T>::LeastSquareSolve(TArray<T>& a, TArray<T> & b)
@@ -170 +188 @@
 
   if (!a.IsPacked(rowa) || !b.IsPacked(rowb))
-     throw(SzMismatchError("LapackServer::LinSolve(a,b) a Or b Not Column Packed"));
-
-  if ( a.Size(rowa) <  a.Size(cola)) 
-    throw(SzMismatchError("LapackServer::LeastSquareSolve(a,b) NRows<NCols "));
-
+     throw(SzMismatchError("LapackServer::LeastSquareSolve(a,b) a Or b Not Column Packed"));
+
+  if ( a.Size(rowa) <  a.Size(cola)) {  // $CHECK$ - m<n a changer
+    cout << " LapackServer<T>::LeastSquareSolve() - m<n - Not yet implemented for "
+         << " underdetermined systems ! " << endl;
+    throw(SzMismatchError("LapackServer::LeastSquareSolve(a,b) NRows<NCols - "));
+  }
   int_4 m = a.Size(rowa);
   int_4 n = a.Size(cola);

trunk/SophyaExt/LinAlg/intflapack.h

@@ -42 +42 @@
 { LapackServer<T> lps; return( lps.LinSolve(a, b) );  }
 
+/*! \ingroup LinAlg
+    \fn LapackLeastSquareSolve(TArray<T>&, TArray<T> &)
+    \brief Solves the linear least squares problem A*X - B
+*/
 template <class T>
 inline int LapackLeastSquareSolve(TArray<T>& a, TArray<T> & b)