PLOTFUN

Plot a given function

Description:

Plot a function specified on the command line by a Fortran-like expression (using TRANSFORM, SUN/61), or through the parameters resulting from a previous fit (using a polynomial or spline).

Usage:

plotfun action expression [xmin] [xmax]

Parameters:

ACTION = _CHAR (Read)
The type of function to be plotted. This must be one of the following:

  • "FUNC" – Use a Fortran-like expression to define the function.

  • "POLY" – Use a set of polynomial coefficients to define the function.

  • "SPLINE" – Use a set of spline coefficients from the file SPLINEFILE to define the function.

[The value is prompted for.]

EXPRESSION = _CHAR (Read)
The Fortran-like expression to be plotted, in terms of X.

[The value is prompted for.]

XMIN = _REAL (Read)
The value of X from which the function is plotted.

[The value of the global parameter PONGO_XMIN is used.]

XMAX = _REAL (Read)
The value of X to which the function is plotted.

[The value of the global parameter PONGO_XMAX is used.]

INFILE = _LOGICAL (Read)
Used when ACTION is "POLY". If TRUE then the polynomial coefficients are stored in a file (the first line of which is the order of the polynomial), otherwise the coefficients are given using the POLYCOEF parameter.

[FALSE]

NPOLY = _INTEGER (Read and Write)
The order of the polynomial: used when ACTION is "POLY".

[The value of the global parameter PONGO_NPOLY is used.]

POLYCOEF = _DOUBLE (Read)
A list of polynomial coefficients: used when ACTION is "POLY".

[The value of the global parameter PONGO_POLYCOEF is used.]

POLYFILE = _CHAR (Read)
The name of a file containing the polynomial coefficients to be plotted. Only used when ACTION is "POLY" and INFILE is TRUE.

[POLYFILE.dat]

SPLINEFILE = FILENAME (Read)
The name of the file containing the coefficients and knot positions from a previous spline fit – used when ACTION is "SPLINE".

[The value of the global parameter PONGO_SPLINEF is used. If PONGO_SPLINEF is not defined, the value is prompted for.]