CDRAW - Draws a 'continuum' using the cursor or by fitting data in a file

Syntax:

CDRAW [filename or mode]

Description:

Allows you to draw a `continuum' using the cursor; the input X values must be in increasing order (CDRAW is terminated with an `X(N+1).LE.X(N)' type test). The result is stored in the `current' arrays (so you should first PUSH your spectrum so as not to lose it); subsequent rectification of data can be carried out using ADIV. (See also CREGD, CREGS and PF).

If MODE=0 (the default value), the data stored are just those input with the cursor, giving a `join-the-dots' spectrum. If MODE=1, a spline fit to the data points is carried out, using the subroutine INTEP described by Hill (Publ DAO). A smooth curve (which is supposed to be like one you might draw by hand through all the cursor points) is calculated on the grid of `x' points of the arrays in the top (i.e. numerically largest) stack entry.

It is possible to input data to this routine from a file, rather than at the terminal. The data are expected to be in the form (NDF or native DIPSO) produced by the WRITE command, and MODE is assumed to be 1 (MODE=0 would have the same effect as a simple READ, and is therefore redundant). Thus, using this option makes CDRAW act essentially as a straightforward spline interpolation routine.