Fix to spinner sampler num_output_points (#1000)

* Missing line in spinner code
* Fix reg test inputs and add comments

amr-wind/utilities/sampling/DTUSpinnerSampler.H

@@ -65,6 +65,11 @@ public:
 
  long num_points() const override { return (m_beam_points * m_ntotal); }
 
+ long num_output_points() const override
+ {
+ return (m_beam_points * m_ntotal);
+ }
+
  void
  define_netcdf_metadata(const ncutils::NCGroup& /*unused*/) const override;
  void

test/test_files/abl_virtual_lidar/abl_virtual_lidar.inp

@@ -64,14 +64,24 @@ sampling.lidar.time_table= 0 10.0
 sampling.lidar.azimuth_table= 0 90.0
 sampling.lidar.elevation_table= 0 45.0
 
-sampling.spinner.type = DTUSpinnerSampler
-sampling.spinner.dt_s = 0.1
-sampling.spinner.num_points = 25
-sampling.spinner.origin = 250.0 250.0 250.0
-sampling.spinner.length= 200.0
-sampling.spinner.time_table= 0 11.0
-sampling.spinner.azimuth_table= 0 90.0
-sampling.spinner.elevation_table= 0 300.0
+sampling.spinner.type = DTUSpinnerSampler
+sampling.spinner.mode = fixed #use "hub" to connect to turbine named below 
+sampling.spinner.turbine = WTG01 #ignored if mode=fixed
+sampling.spinner.hub_debug = false
+sampling.spinner.inner_prism_theta0 = 90
+sampling.spinner.inner_prism_rotrate = 3.5
+sampling.spinner.inner_prism_azimuth = 15.2
+sampling.spinner.outer_prism_theta0 = 90
+sampling.spinner.outer_prism_rotrate = 6.5
+sampling.spinner.outer_prism_azimuth = 15.2
+sampling.spinner.lidar_center = 250.0 250.0 250.0 #this gets overwritten for "hub" mode
+sampling.spinner.scan_time = 2
+sampling.spinner.num_samples = 984
+sampling.spinner.beam_length = 100.0
+sampling.spinner.beam_points = 25
+sampling.spinner.fixed_yaw = 0
+sampling.spinner.fixed_roll = 0
+sampling.spinner.fixed_tilt = 0