Merge pull request #1495 from robbietuk/get_axial_length_for_cylindrical

Add support for get_axial_length for cylindrical scanners.

src/include/stir/Scanner.h

@@ -426,6 +426,7 @@ class Scanner
   inline float get_transaxial_block_spacing() const;
   /*! get total axial length covered by the detectors (incl. any gaps between blocks etc.)
     \todo Need to update this function when enabling different spacing between blocks and buckets etc.
+    For cylindrical scanners, calculates the length by the ring spacing.
   */
   inline float get_axial_length() const;
   //@} (end of get block geometry info)

src/include/stir/Scanner.inl

@@ -298,6 +298,14 @@ Scanner::get_axial_block_spacing() const
 float
 Scanner::get_axial_length() const
 {
+  if (get_scanner_geometry() == "Cylindrical")
+    {
+      return get_num_rings() * get_ring_spacing();
+    }
+  else if (get_scanner_geometry() == "Generic")
+    {
+      error("get_axial_length not yet implemented for Generic scanner geometry");
+    }
   return get_num_axial_buckets() * get_num_axial_blocks_per_bucket() * get_axial_block_spacing()
          - (get_axial_block_spacing() - (get_num_axial_crystals_per_block() - 1) * get_axial_crystal_spacing());
 }