4.17 sddscollapse

• description: sddscollapse reads data pages from an SDDS file and writes a new SDDS file containing a single data page. This data page contains only the values of the parameters from the original file, with each parameter forming a column of the tabular data.
• examples: To create a new file containing the tunes and other parameters as columns:

  sddscollapse APS.twi APS.parameters

  To do a polynomial fit to nux as a function of nuy, and print the results out:

  sddscollapse APS.twi -pipe=out | sddspfit -pipe=in fit.sdds -column=nux,nuy -verbose

• synopsis:

  sddscollapse [inputFile] [outputFile] [-pipe[=input][,output]]

• files: inputFile is the name of an SDDS data set to be collapsed. outputFile is the result. Note that outputFile will not contain any information on the arrays or columns that are in inputFile.
• switches:
  • -pipe[=input][,output] — The standard SDDS Toolkit pipe option.
  • -noWarnings — Suppresses warnings about file overwrites.
• comment: In spite of the simplicity of the commandline, this is an extremely useful program. A typical use might involve processing a multipage file using sddsprocess to, for example, obtain statistical analyses of columns for each page; the results of such analyses are placed in parameters. Using sddscollapse on this file would produce columns of statistical analyses, with one row for each page. One might then further analyze the data using sddsprocess. One could also use sddscombine to combine several collapsed, processed data sets into a single file, which puts one formally back in the same position as when one started. In this fashion, multi-level data analysis and collation is possible. This is done with some magnetic measurements at APS.
• see also:
  • Data for Examples
  • sddsprocess
  • sddscombine
  • sddsexpand
• author: M. Borland, ANL/APS.