commit b16e118b96c55451c0d8556f3c5b52ad36b69cac
author Sameer Agarwal <sameeragarwal@google.com> Mon Nov 25 05:47:43 2013 -0800
committer Sameer Agarwal <sameeragarwal@google.com> Tue Nov 26 10:00:03 2013 -0800
tree 2d5322d2f9fafde0a298e95356f70962acc57957
parent 5794d41be2d8d6a67dcdfe607e66050f0ac04c55

Better error checking and reporting for linear solvers.

A lot of error checking cruft has accumulated over the years
in the various linear solvers. This change makes the error reporting
more robust and consistent across the various solvers.

Preconditioners are not covered by this change and will be the
subject of a future change.

Change-Id: Ibeb2572a1e67758953dde8d12e3abc6d1df9052d

internal/ceres/lapack.cc

diff --git a/internal/ceres/lapack.cc b/internal/ceres/lapack.cc
index e93e05f..0061433 100644
--- a/internal/ceres/lapack.cc
+++ b/internal/ceres/lapack.cc
@@ -29,6 +29,9 @@
 // Author: sameeragarwal@google.com (Sameer Agarwal)
 
 #include "ceres/lapack.h"
+
+#include "ceres/internal/port.h"
+#include "ceres/linear_solver.h"
 #include "glog/logging.h"
 
 // C interface to the LAPACK Cholesky factorization and triangular solve.
@@ -63,12 +66,14 @@
 namespace ceres {
 namespace internal {
 
-int LAPACK::SolveInPlaceUsingCholesky(int num_rows,
-                                      const double* in_lhs,
-                                      double* rhs_and_solution) {
+LinearSolverTerminationType LAPACK::SolveInPlaceUsingCholesky(
+    int num_rows,
+    const double* in_lhs,
+    double* rhs_and_solution,
+    string* status) {
 #ifdef CERES_NO_LAPACK
   LOG(FATAL) << "Ceres was built without a BLAS library.";
-  return -1;
+  return FATAL_ERROR;
 #else
   char uplo = 'L';
   int n = num_rows;
@@ -77,17 +82,33 @@
   double* lhs = const_cast<double*>(in_lhs);
 
   dpotrf_(&uplo, &n, lhs, &n, &info);
-  if (info != 0) {
-    LOG(INFO) << "Cholesky factorization (dpotrf) failed: " << info;
-    return info;
+  if (info < 0) {
+    LOG(FATAL) << "Congratulations, you found a bug in Ceres."
+               << "Please report it."
+               << "LAPACK::dpotrf fatal error."
+               << "Argument: " << -info << " is invalid.";
+    return FATAL_ERROR;
+  }
+
+  if (info > 0) {
+    *status =
+        StringPrintf(
+            "LAPACK::dpotrf numerical failure. "
+             "The leading minor of order %d  is not positive definite.", info);
+    return FAILURE;
   }
 
   dpotrs_(&uplo, &n, &nrhs, lhs, &n, rhs_and_solution, &n, &info);
-  if (info != 0) {
-    LOG(INFO) << "Triangular solve (dpotrs) failed: " << info;
+  if (info < 0) {
+    LOG(FATAL) << "Congratulations, you found a bug in Ceres."
+               << "Please report it."
+               << "LAPACK::dpotrs fatal error."
+               << "Argument: " << -info << " is invalid.";
+    return FATAL_ERROR;
   }
 
-  return info;
+  *status = "Success";
+  return TOLERANCE;
 #endif
 };
 
@@ -113,20 +134,27 @@
          &lwork,
          &info);
 
-  CHECK_EQ(info, 0);
+  if (info < 0) {
+    LOG(FATAL) << "Congratulations, you found a bug in Ceres."
+               << "Please report it."
+               << "LAPACK::dgels fatal error."
+               << "Argument: " << info << " is invalid.";
+  }
   return static_cast<int>(work);
 #endif
 }
 
-int LAPACK::SolveUsingQR(int num_rows,
-                         int num_cols,
-                         const double* in_lhs,
-                         int work_size,
-                         double* work,
-                         double* rhs_and_solution) {
+LinearSolverTerminationType LAPACK::SolveInPlaceUsingQR(
+    int num_rows,
+    int num_cols,
+    const double* in_lhs,
+    int work_size,
+    double* work,
+    double* rhs_and_solution,
+    string* status) {
 #ifdef CERES_NO_LAPACK
   LOG(FATAL) << "Ceres was built without a LAPACK library.";
-  return -1;
+  return FATAL_ERROR;
 #else
   char trans = 'N';
   int m = num_rows;
@@ -149,7 +177,15 @@
          &work_size,
          &info);
 
-  return info;
+  if (info < 0) {
+    LOG(FATAL) << "Congratulations, you found a bug in Ceres."
+               << "Please report it."
+               << "LAPACK::dgels fatal error."
+               << "Argument: " << -info << " is invalid.";
+  }
+
+  *status = "Success.";
+  return TOLERANCE;
 #endif
 }