Name: PGFUNX Purpose: function defined by Y = F(X) Category: GRAPHICS File: pgplot.src Author: T.J. Pearson Use: see description below. Description: SUBROUTINE PGFUNX (FY, N, XMIN, XMAX, PGFLAG) REAL FY EXTERNAL FY INTEGER N REAL XMIN, XMAX INTEGER PGFLAG Draw a curve defined by the equation Y = FY(X), where FY is a user-supplied subroutine. Arguments: FY (external real function): supplied by the user, evaluates Y value at a given X-coordinate. N (input) : the number of points required to define the curve. The function FY will be called N+1 times. If PGFLAG=0 and N is greater than 1000, 1000 will be used instead. If N is less than 1, nothing will be drawn. XMIN (input) : the minimum value of X. XMAX (input) : the maximum value of X. PGFLAG (input) : if PGFLAG = 1, the curve is plotted in the current window and viewport; if PGFLAG = 0, PGENV is called automatically by PGFUNX to start a new plot with X limits (XMIN, XMAX) and automatic scaling in Y. Note: The function FY must be declared EXTERNAL in the Fortran program unit that calls PGFUNX. It has one argument, the x-coordinate at which the y value is required, e.g. REAL FUNCTION FY(X) REAL X FY = ..... END Note: This subroutine is only callable from Fortran, not from C. Updates: Oct 16, 1998: JPT automatically extracted from source.