2.1 File formats

KUPLOT reads data sets using the 'load' command. The simplest file format is a text file containing values for x and y on a separate line for each data point as in the previous example. To read more than one data set just repeat the 'load' command. The maximum number of data sets that can be read and the maximum total number of data points are defined in the file 'kuplot.inc' and might be adjusted before KUPLOT is compiled. The current limits can be displayed using the command 'show config'. The 'rese' command clears the currently loaded data sets and the next file is read as data set one again.

 

Table 2.1: Supported file formats for 1D data

Format	Description
cr	Special crystal structure format exported by DISCUS. Each line contains x,y,z, marker type, colour and marker size for the atom at the given coordinates. Note, the first two columns are uses for plotting, the z value is ignored (see DISCUS plot sublevel).
ma	Only the x value of each data line is read, y is set to zero. This allows the plotting of tickmarks (e.g. at Bragg peak positions in powder diffraction data) at the x-axis.
sc/st	This command allows one to read scans from a SPEC file. For details refer to the online help.
xx	Each line contains only one value that is taken as y value and the point number is stored as x value.
xy	Each line of the data file contains x,y and optionally standard deviations $\sigma_{x}$ and $\sigma_{y}$.
yx	Each line of the data file contains y,x and optionally standard deviations $\sigma_{y}$ and $\sigma_{x}$.
special	Various other file formats are available to read specific information from data files created by the diffractometer control software for the instruments MAN I and MAN II at the FRM I. For details refer to the online help for the command 'load'.

The various file formats for 1D data supported by KUPLOT are summarized in Table 2.1. The file format is specified as first parameter for the 'load' command followed by the name of the file to be read. Note that the 'xy' and 'yx' formats may contain standard deviations $\sigma_{x,y}$ for each data point which may be used to plot error bars using the 'etyp' command in KUPLOT.

After a data set is read, KUPLOT displays the number of points read and the x- and y-limits. In our previous example, the screen output after entering the 'load xy,test.xy' looks like that:

    Reading 2 columns ...
    Data set no.:   1

      Filename : test.xy                            (     8 points )
      Range  x :   -2.000     to    6.000
      Range  y :   -3.000     to    24.00

Since our example file contains no $\sigma$ values, KUPLOT can only read two columns. The file is associated with data set 1. This data set number is subsequently used to alter the appearance of the plot for a given data set (see next section).