Last minutes' change.

git-svn-id: file:///home/svnrepos/software/liblbfgs/trunk@16 ecf4c44f-38d1-4fa4-9757-a0b4dd0349fc

include/lbfgs.h

@@ -263,7 +263,7 @@ typedef struct {
      *  (i.e., \ref orthantwise_c != 0). This parameter b (0 <= b < N)
      *  specifies the index number from which the library computes the
      *  L1 norm of the variables x,
-     *      |x| := |x_{b} + x_{b+1} + ... + x_{N}|
+     *      |x| := |x_{b}| + |x_{b+1}| + ... + |x_{N}| .
      *  In other words, variables x_1, ..., x_{b-1} are not used for
      *  computing the L1 norm. Setting b (0 < b < N), one can protect
      *  variables, x_1, ..., x_{b-1} (e.g., a bias term of logistic

lib/lbfgs.c

@@ -355,10 +355,12 @@ int lbfgs(
     }
 
     /*
-       Make sure that the gradients are not zero.
+       Make sure that the initial variables are not a minimizer.
      */
     vecnorm(&gnorm, g, n);
-    if (gnorm == 0.) {
+    vecnorm(&xnorm, x, n);
+    if (xnorm < 1.0) xnorm = 1.0;
+    if (gnorm / xnorm <= param->epsilon) {
         ret = LBFGS_ALREADY_MINIMIZED;
         goto lbfgs_exit;
     }