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1. Cyrill
   

   Member
   Joined: Nov '18
   Posts: 6

   I have been building on the example for B-mode Images Using A Phased Array. However, when using the C++ code (either CPU or CUDA) in MATLAB I get inconsistent results with the OMP results. Unfortunately, I don’t get either code to misbehave and even after hours in the forum I’m struggling to make any headway – but at least I learned a lot!!

   Running the C++ code directly from MATLAB:

   for angle_index = 1:number_scan_lines
   transducer.steering_angle = steering_angles(angle_index);
   sensor_data = kspaceFirstOrder3DG(kgrid, medium, transducer, transducer, input_args{:});
   scan_lines(angle_index, :) = transducer.scan_line(sensor_data);
   end

   Running the OMP code:

   for angle_index = 1:number_scan_lines
   transducer.steering_angle = steering_angles(angle_index);
   filename=sprintf('input_orig_%d.h5',angle_index);
   kspaceFirstOrder3D(kgrid, medium, transducer, transducer, input_args{:},'SaveToDisk',filename);
   end

   Run on cluster: kspaceFirstOrder-OMP -i input_orig_##.h5 -o output_orig_##.h5

   for angle_index = 1:number_scan_lines
   filename = sprintf('output_orig_%d.h5',angle_index);
   sensor_data = h5read(filename,'/p');
   sensor_data = transducer.combine_sensor_data(sensor_data);
   scan_lines(angle_index, :) = transducer.scan_line(sensor_data);
   end

   Posted 3 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,640

   Hi Cyrill,

   Can you try the following:

   1. When you call kspaceFirstOrder3DG, set the optional input 'DataPath' to save the input file somewhere you can access easily, and set 'DeleteData', false.

   2. Use h5compare to compare the input file created by kspaceFirstOrder3DG and the file you create manually.

   They should be identical (both use kspaceFirstOrder3D to create the input file).

   Also, have you set values for sensor.record_start_index? If so, this should be passed to the code on the cluster using the -s command line input.

   Brad.

   Posted 3 years ago #

3. Cyrill
   

   Member
   Joined: Nov '18
   Posts: 6

   Thanks Brad for the help! With your advise I tracked down that all files were indeed identical (including sensor_data) and the problem was that I had not updated the transducer class on the readout:

   for angle_index = 1:number_scan_lines
   % update the current steering angle
   transducer.steering_angle = steering_angles(angle_index);
   filename = sprintf('output_orig_%d.h5',angle_index);
   sensor_data = h5read(filename,'/p');
   sensor_data = transducer.combine_sensor_data(sensor_data);
   scan_lines(angle_index, :) = transducer.scan_line(sensor_data);
   end

   Everything works now - thanks!!

   Posted 3 years ago #

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