USAGE: rpft LL=a UL=b NN=n ND=m [-DIG=n -XLN -YLN] file
LL=a a is the lower limit of theregion for fit
UL=b b is the upper limit of the region for fit
ND=m | m>0: rational function, denominator degree m,
NN=n | numerator degree n. 1<=m<=10 1<=n<=10
| m=0: Polynomial degree n. 1<=n<=20
-DIG=n (optional) n = number of significant digits
for coefficients on output. Default=7.
-XLN (optional) Transform X values to ln(X)
-YLN (optional) Transform Y values to ln(Y)
file File with input X Y data points, 1 per line
All command line parameters except DIG, XLN and YLN are
required. They may be in any order, upper or lower case