CLOG

Take the logarithm of a column

Description:

Take the base 10 logarithm of a data column. This application should be used to take the logarithm of the data columns in preference to doing it with CCMATH, because it can deal with the associated error values consistently. It automatically adds the "L" option to the PONGO_XOPT or PONGO_YOPT global parameters, as appropriate.

Usage:

clog action

Parameters:

ACTION = _CHAR (Read)
The data column to transform. It should be one of the following:

  • "X" – XCOL,

  • "Y" – YCOL,

  • "Z" – ZCOL.

[The value will be prompted for.]

XOPT = _CHAR (Write)
The PGPLOT X-axis options string. The global parameter will be updated to include the PGPLOT "L" axis option at the start. This option means that logarithmic style axis labels and tick marks will be plotted. The READF command will automatically remove any "L" characters at the start of this string since it assumes that they have been put there by CLOG, and fresh data read in will not be logarithmic. If data are naturally logarithmic, the "L" should be placed other than at the start of the string to make an "L" option that will not be modified by PONGO.

It is not intended that this parameter be set by you when CLOG is executed.

The value will be written to the global parameter PONGO_XOPT.

YOPT = _CHAR (Write)
The PGPLOT Y-axis options string. Its action is similar to the XOPT parameter. It is not intended that this parameter be set by you when CLOG is executed.

The value will be written to the global parameter PONGO_YOPT.