4.101 sddssnap2grid

• description: sddssnap2grid reads data pages from an SDDS file and writes a new SDDS file. The output data contains all of the input data, except that one or more columns may be modified to “snap” the values to a uniform grid.
• examples:
  sddssnap2grid fieldMap.sdds fieldMap1.sdds -column=x -column=y -column=z  
  sddssnap2grid fieldMap.sdds fieldMap1.sdds -column=x -column=y -column=z,deltaGuess=5e-4  
    

• synopsis:
  sddssnap2grid [<options>] inputFile outputFile  
    

• switches:
  • -pipe[=input][,output] — The standard SDDS Toolkit pipe option.
  • -column=name[{maximumBins=value | binFactor=value} | deltaGuess=value] — Specifies a column to be snapped to a grid. The column must contain numerical data. The algorithm uses histograms to group the data points into subsets; this grouping is considered valid if there are no adjacent bins in the histogram that have non-zero values. By default, the number of bins is 10 times the number of data points, which seems reliable if data is actually close to a grid. If the algorithm fails, the user can provide additional parameters to attempt to obtain a good result. The first thing to try is providing a guess of the grid spacing using deltaGuess; in this case the initial number of bins is based on 10 times the provided spacing. Next, one can try providing a value for the binFactor parameter that is higher or lower than 10. Finally, the maximumBins parameter can be set directly.
  • -verbose — Prints grid parameters to standard output.
• files: inputFile is the name of an SDDS data set to be snapped. outputFile is the result.
• author: M. Borland, ANL/APS.