4.88 sddsvslopes

• description: sddsvslopes makes straight line fits of vectorized data in the input file with respect to a selected parameter used as independent variable. The simplest example of vectorized data is a data set with one parameter and two columns, one string column of rootnames and one numerical column of data. The fitting is looped over rows across all the data sets in the input file (using a selected parameter as the independent vairable). The output file contains vectorized slopes and intercepts data for each column specified in the input file.
• examples: The file corrector.sdds contains vectorized beam position monitor (bpm) readbacks as a function of corrector setting. The defined parameter is CorrectorSetpoint. The defined columns are Rootname and x. Each row of the data set correspond to a different bpm. The bpm response to the corrector setpoints are calculated with

  sddsvslopes corrector.sdds corrector.vslopes -independentVariable=CorrectorSetpoint -columns=x

• synopsis:

  sddsvslopes [-pipe=[input][,output]] inputFile outputFile -independentVariable=parametername [-columns=listOfNames] [-excludeColumns=listOfNames] [-sigma[=generate]] [-verbose]

• files: The input file contains the tabular data for fitting. The column Rootname must be present.

  The output file contains one data set of vectorized slopes and intercept data. The Rootname and Index columns from the input file is transfered to the output file. In the column Index doesn’t exist in the input file, then it is created in the output file anyway. The column names are nameSlope, and nameIntercept where name is the name of the fitted data. If only one file is specified, then the input file is overwritten by the output. A string parameter called IndenpendentVariable is defined containing the name of the indepedent variable.

• switches:
  • -pipe[=input][,output] — The standard SDDS Toolkit pipe option.
  • -independentVariable=parametername — name of independent variable (default is the first valid column)
  • -columns=listOfNames — columns to be individually paired with independentVariable for straight line fitting
  • -excludeColumns=listOfNames — columns to exclude from fitting
  • -sigma[=generate] — calculates errors by interpreting column names nameSigma or Sigmaname as sigma of column name. If these columns don’t exist then the program generates a common sigma from the residual of a first fit, and refits with these sigmas. If option -sigma=generate is given, then sigmas are generated from the residual of a first fit for all columns, irrespective of the presence of columns nameSigma or Sigmaname.
  • -ascii — make output file in ascii mode (binary is the default)
  • -verbose — prints some output to stderr
• author: L. Emery ANL