4.14 sddschanges

• description: sddschanges analyzes changes in column data from page to page in a file, relative to reference data in a baseline file or from the first page. It requires that every page in the file have the same number of rows. It produces a multipage output file containing the row-by-row difference between the reference data and the data each page in the input file.
• examples: Compute the changes in the dispersion function for several APS lattices:

  sddschanges APS.twi APS.changes -copy=s -changesIn=betax,betay,etax

  The output file in this example would have one fewer pages than the input file. Each page would contain the column s from the first page, along with the differences from the first page for betax, betay, and etax. One could also compute the changes relative to the nominal lattice:

  sddschanges APS.twi -baseline=APS0.twi APS.changes -copy=s -changeIn=betax,betay,etax

  The output file would have one page for every page in the input.

• synopsis:

  sddschanges [-pipe[=input][,output]] [inputFile] [outputFile] [-copy=columnNames] [-changesIn=columnNames] [-baseline=referenceFileName [-parallelPages]]

• files: inputFile is a multipage file containing the data for which changes are desired. outputFile is a multipage file containing the changes. The column names in outputFile for the changes are created from those in inputFile by prepending the string “ChangeIn”.
• switches:
  • -pipe=[input][,output] — The standard SDDS Toolkit pipe option.
  • -copy=columnNames— Specifies that the named columns should be transferred to the output file without alteration. These data come from the baseline file or from the first page of the input file. A comma-separated list of optionally wildcard-containing strings may be given.
  • -changesIn=columnNames — Specifies that the named columns should be transferred to the output file after subtracting the corresponding values from the baseline file or from the first page of the input file. A comma-separated list of optionally wildcard-containing strings may be given.
  • -baseline=referenceFileName — Specifies the name of an SDDS file from which the reference data for changes should be taken.
  • -parallelPages — Valid only with -baseline. Specifies that the “baseline” data for each page of the input file shall be taken from the corresponding page of the baseline file. This results in page-by-page subtraction of the two files.
• see also:
  • Data for Examples
  • sddsenvelope
• author: M. Borland, ANL/APS.