one side derivatives

polyfem · Jun 7, 2024 · e7e41ad · e7e41ad
1 parent 4438ac2
commit e7e41ad
Showing 1 changed file with 5 additions and 2 deletions.
diff --git a/src/polysolve/nonlinear/Solver.cpp b/src/polysolve/nonlinear/Solver.cpp
@@ -580,6 +580,7 @@ namespace polysolve::nonlinear
     void Solver::verify_gradient(Problem &objFunc, const TVector &x, const TVector &grad)
     {
         bool match = false;
+        double J = objFunc(x);
 
         switch (gradient_fd_strategy)
         {
@@ -598,15 +599,17 @@ namespace polysolve::nonlinear
             double J1 = objFunc(x1);
 
             double fd = (J2 - J1) / 2 / gradient_fd_eps;
+            double fd_right = (J2 - J) / gradient_fd_eps;
+            double fd_left = (J - J1) / gradient_fd_eps;
             double analytic = direc.dot(grad);
 
             match = abs(fd - analytic) < 1e-8 || abs(fd - analytic) < 1e-4 * abs(analytic);
 
             // Log error in either case to make it more visible in the logs.
             if (match)
-                m_logger.debug("step size: {}, finite difference: {}, derivative: {}", gradient_fd_eps, fd, analytic);
+                m_logger.debug("step size: {}, finite difference: {} {} {}, derivative: {}", gradient_fd_eps, fd, fd_left, fd_right, analytic);
             else
-                m_logger.error("step size: {}, finite difference: {}, derivative: {}", gradient_fd_eps, fd, analytic);
+                m_logger.error("step size: {}, finite difference: {} {} {}, derivative: {}", gradient_fd_eps, fd, fd_left, fd_right, analytic);
         }
         break;
         case FiniteDiffStrategy::FULL_FINITE_DIFF: