Prefer std::isnan over != comparison trick

apps/point_cloud_editor/src/trackball.cpp

@@ -165,7 +165,7 @@ TrackBall::update(int s_x, int s_y)
   normalize(cross_x, cross_y, cross_z, nc_x, nc_y, nc_z);
 
   quat_ = quaternionFromAngleAxis(angle, nc_x, nc_y, nc_z);
-  if (quat_.R_component_1() != quat_.R_component_1())
+  if (std::isnan(quat_.R_component_1()))
     quat_ = boost::math::quaternion<float>(1.0f);
 
   origin_x_ = cur_x;

features/include/pcl/features/impl/3dsc.hpp

@@ -261,7 +261,7 @@ pcl::ShapeContext3DEstimation<PointInT, PointNT, PointOutT>::computePoint (
     assert (w >= 0.0);
     if (w == std::numeric_limits<float>::infinity ())
       PCL_ERROR ("Shape Context Error INF!\n");
-    if (w != w)
+    if (std::isnan(w))
       PCL_ERROR ("Shape Context Error IND!\n");
     /// Accumulate w into correspondent Bin(j,k,l)
     desc[(l*elevation_bins_*radius_bins_) + (k*radius_bins_) + j] += w;

features/include/pcl/features/impl/usc.hpp

@@ -233,7 +233,7 @@ pcl::UniqueShapeContext<PointInT, PointOutT, PointRFT>::computePointDescriptor (
     assert (w >= 0.0);
     if (w == std::numeric_limits<float>::infinity ())
       PCL_ERROR ("Shape Context Error INF!\n");
-    if (w != w)
+    if (std::isnan(w))
       PCL_ERROR ("Shape Context Error IND!\n");
     /// Accumulate w into correspondent Bin(j,k,l)
     desc[(l*elevation_bins_*radius_bins_) + (k*radius_bins_) + j] += w;

people/include/pcl/people/impl/head_based_subcluster.hpp

@@ -255,7 +255,7 @@ template <typename PointT> void
 pcl::people::HeadBasedSubclustering<PointT>::subcluster (std::vector<pcl::people::PersonCluster<PointT> >& clusters)
 {
   // Check if all mandatory variables have been set:
-  if (sqrt_ground_coeffs_ != sqrt_ground_coeffs_)
+  if (std::isnan(sqrt_ground_coeffs_))
   {
     PCL_ERROR ("[pcl::people::pcl::people::HeadBasedSubclustering::subcluster] Floor parameters have not been set or they are not valid!\n");
     return;

people/include/pcl/people/impl/height_map_2d.hpp

@@ -59,7 +59,7 @@ template <typename PointT> void
 pcl::people::HeightMap2D<PointT>::compute (pcl::people::PersonCluster<PointT>& cluster)
 {
   // Check if all mandatory variables have been set:
-  if (sqrt_ground_coeffs_ != sqrt_ground_coeffs_)
+  if (std::isnan(sqrt_ground_coeffs_))
   {
     PCL_ERROR ("[pcl::people::HeightMap2D::compute] Floor parameters have not been set or they are not valid!\n");
     return;

registration/include/pcl/registration/impl/ndt.hpp

@@ -132,7 +132,7 @@ pcl::NormalDistributionsTransform<PointSource, PointTarget>::computeTransformati
     //Calculate step length with guarnteed sufficient decrease [More, Thuente 1994]
     delta_p_norm = delta_p.norm ();
 
-    if (delta_p_norm == 0 || delta_p_norm != delta_p_norm)
+    if (delta_p_norm == 0 || std::isnan(delta_p_norm))
     {
       trans_probability_ = score / static_cast<double> (input_->points.size ());
       converged_ = delta_p_norm == delta_p_norm;
@@ -368,7 +368,7 @@ pcl::NormalDistributionsTransform<PointSource, PointTarget>::updateDerivatives (
   e_x_cov_x = gauss_d2_ * e_x_cov_x;
 
   // Error checking for invalid values.
-  if (e_x_cov_x > 1 || e_x_cov_x < 0 || e_x_cov_x != e_x_cov_x)
+  if (e_x_cov_x > 1 || e_x_cov_x < 0 || std::isnan(e_x_cov_x))
     return (0);
 
   // Reusable portion of Equation 6.12 and 6.13 [Magnusson 2009]
@@ -459,7 +459,7 @@ pcl::NormalDistributionsTransform<PointSource, PointTarget>::updateHessian (Eige
   double e_x_cov_x = gauss_d2_ * exp (-gauss_d2_ * x_trans.dot (c_inv * x_trans) / 2);
 
   // Error checking for invalid values.
-  if (e_x_cov_x > 1 || e_x_cov_x < 0 || e_x_cov_x != e_x_cov_x)
+  if (e_x_cov_x > 1 || e_x_cov_x < 0 || std::isnan(e_x_cov_x))
     return;
 
   // Reusable portion of Equation 6.12 and 6.13 [Magnusson 2009]

surface/include/pcl/surface/organized_fast_mesh.h

@@ -362,7 +362,7 @@ namespace pcl
         if (cos_angle_tolerance_ > 0)
         {
           float cos_angle = dir_a.dot (dir_b) / (distance_to_points*distance_between_points);
-          if (cos_angle != cos_angle)
+          if (std::isnan(cos_angle))
             cos_angle = 1.0f;
           bool check_angle = fabs (cos_angle) >= cos_angle_tolerance_;