cmd/*.cpp: Address minor issues identified by clang-tidy

cmd/dwi2fod.cpp

@@ -32,7 +32,7 @@ using namespace App;
 const char *const algorithms[] = {"csd", "msmt_csd", NULL};
 
 // clang-format off
-OptionGroup CommonOptions = OptionGroup ("Options common to more than one algorithm")
+const OptionGroup CommonOptions = OptionGroup ("Options common to more than one algorithm")
 
   + Option ("directions",
             "specify the directions over which to apply the non-negativity constraint"

cmd/mraverageheader.cpp

@@ -45,7 +45,7 @@ void usage() {
   OPTIONS
   + Option ("padding", " boundary box padding in voxels."
                        " Default: " + str(PADDING_DEFAULT))
-    + Argument ("value").type_float(0.0, std::numeric_limits<default_type>::infinity())
+    + Argument ("value").type_float(0.0)
 
   + Option ("resolution", "subsampling of template compared to smallest voxel size in any input image."
                           "Valid options are: "

cmd/mrcolour.cpp

@@ -40,7 +40,7 @@ void usage() {
     if (strcmp(entry->name, "Complex"))
       colourmap_choices_std.push_back(lowercase(entry->name));
     ++entry;
-  } while(entry->name);
+  } while(entry->name != nullptr);
   colourmap_choices_cstr.reserve(colourmap_choices_std.size() + 1);
   for (const auto& s : colourmap_choices_std)
     colourmap_choices_cstr.push_back(s.c_str());

cmd/mrfilter.cpp

@@ -91,10 +91,10 @@ const OptionGroup SmoothOption = OptionGroup ("Options for smooth filter")
 const OptionGroup ZcleanOption = OptionGroup ("Options for zclean filter")
   + Option ("zupper", "define high intensity outliers;"
                       " default: 2.5")
-    + Argument ("num").type_float(0.1, std::numeric_limits<float>::infinity())
+    + Argument ("num").type_float(0.1)
   + Option ("zlower", "define low intensity outliers;"
                       " default: 2.5")
-    + Argument ("num").type_float(0.1, std::numeric_limits<float>::infinity())
+    + Argument ("num").type_float(0.1)
   + Option ("bridge", "number of voxels to gap to fill holes in mask;"
                       " default: 4")
     + Argument ("num").type_integer(0)

cmd/tckconvert.cpp

@@ -99,7 +99,7 @@ void usage() {
     + OptionGroup ("Options for both PLY and RIB writer")
 
     + Option ("radius", "radius of the streamlines")
-      + Argument("radius").type_float(0.0f)
+      + Argument("radius").type_float(0.0)
 
     + OptionGroup ("Options specific to VTK writer")