Python analysis class

General notes

• Matlab starts indexing with 1, python starts with 0. We always have to shift the index properly in python!
• Different data are matched using a "common index" concept: all scalars and each camera has its own "common index". We first have to find the common index and then use it to index the actual data arrays, if we want data that belong to the same shot.

Matlab file

• Load the file using: "facetdata        = facet.FacetDataFile(filename)"

Main structure

• Print the central keys using: "facetdata.print_keys()"
  
• Print the key entries of "data_struct" using: "facetdata.print_data_entries()"
  
  

params

• Print all entries using: "facetdata.print_params_entries()"
  
  

• Get information about the scan:

  print("number of steps:          ", facetdata.nSteps)
  print("number of shots per step: ", facetdata.n_shot)

  

  facetdata.print_scanPVs()
  facetdata.print_scanVals()

  
  
  
  

scalars

List all entries

• using: "facetdata.print_scalars_entries()"
  
  
  

Common index concept

• We explain the "common index" concept using "steps" as an example
  print all steps: "facetdata.print_steps()"
  
• The list contains much more than just 20 x 50 = 1000 entries (number of shots per step x number of steps)
• To get the number of successful shots:
  

  shotidx_list        = facetdata.get_shotidx_list()
  print("number of shots: ", facetdata.get_scan_length())
  print("shot idx:        ", shotidx_list)

  
  
  
  Note that the function "get_shotidx_list()" returns a "LinData" object that represents a list of all successful shots
  
  
• To access scalar variables properly, we need to use the scalar common index:
  use the function "facetdata.get_scalar_cidx" to convert a shot index to a common index.
  
  
• This is how it is done internally:
  
• We can get a  "LinData" object with all scan values using "facetdata.get_scan_value_list()"
  
• We can plot the scanned values:
  
  

  plot            = facet.FacetPlot(facetdata)
  plot.set_output_folder(output_folder)
  plot.scatter(shotidx_list, scan_value_list, colorylabel=False) 
  plot.save("scan_values", png=True)

  
  

Access scalar variables through lists

• The lists are loaded during initialization; access them, e.g., using:
  print(facetdata.BSA_List_S20.dtype)
  
  
  
• Access them using a "FacetScalar" object:
  

  bpm_3218_x            = facet.FacetScalar(facetdata, "BSA_List_S20", "BPMS_LI20_3218_X").get_data()
  bpm_3218_y            = facet.FacetScalar(facetdata, "BSA_List_S20", "BPMS_LI20_3218_Y").get_data()

  plot            = facet.FacetPlot(facetdata)
  plot.set_output_folder(output_folder)
  plot.scatter(bpm_3218_x, bpm_3218_y, colorylabel=False)  
  plot.save("bpm_3218", png=True)