Input and Output Functions

From LIBISIS
Revision as of 12:04, 17 March 2008 by Dean Whittaker (talk | contribs)
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ASCII Files

  • IXTdataset_1d objects may be stored in ASCII files.
  • These files may contain x and y data or x, y, error data in a 2 or 3 column format.
  • Column 1 will be x values, column 2 will be y values and if available column 3 will be error values, if not available then error is assumed to be 0.
  • Any information at the start or end of the file that is not in a 2 or 3 column format is ignored (for instance, header information may be stored here).
  • Columns may be separated by commas, tabs, or spaces.
  • ASCII files may contain point or histogram data, the x column in histogram data will have one more value than the y and e columns.
  • The following files would all be acceptable ASCII files
  
title = plots1 xaxis = wavelength yaxis = signal 
490.2 30000
491.2 31923
492.2 40000

Represents a three point dataset with 0 error

  
title = plots1 xaxis = wavelength yaxis = signal 
490.2 30000 300
491.2 31923 300 
492.2 40000 250
493.2

Represents a 3 column histogram dataset with error data

  
490.2,30000,300
491.2,31923,300
492.2,40000,250
493.2

Will represent the same 3 column histogram dataset with error data.

  • When files are written by libisis a header is written at the top of the file with the following information
    name = dataset name
    title = dataset title 
    signal_units = dataset s axis label 
    x_units = dataset x axis label
    x_distribution = 1

x1 s1 e1
x2 s2 e2 
...

where the header information is taken from the dataset being written.

To read and write data to ASCII files in


Point Data

Histogram Data

RAW Files

Other Formats

Reading Data

From a RAW File

From an ASCII File

From Other Sources

Writing Data

To an ASCII File

To a Binary File

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