Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!iuvax!pur-ee!pur-phy!murphy
From: murphy@pur-phy (William J. Murphy)
Newsgroups: comp.lang.pascal
Subject: What is sngl()?
Summary: From Numerical Recipes listing
Message-ID: <1510@pur-phy>
Date: 7 Oct 88 20:50:26 GMT
Reply-To: murphy@newton.physics.purdue.edu.UUCP (William J. Murphy)
Organization: Purdue Univ. Physics Dept., W. Lafayette, IN
Lines: 19


I am translating one of the FFT routines in Numerical Recipes, and have 
come across a function/statement I don't understand.  I do not know standard
Pascal, I have only just learned Turbo Pascal 4.0.

In PROCEDURE four1, the for loop jj contains the following statement.

tempr := sngl(wr) * data[j] - sngl(wi) * data[j+1];

WHAT does sngl(wr) do?  Is it a type cast, tempr is a real and wr is double.
If so, what does this translate to in Turbo-Pascal 4.0?  I recall reading
that typecasts in Turbo require the same sized variables which implies I
can't cast a double into a real.  

Please enlighten me. I am not a regular reader of comp.lang.pascal, so e-mail
is my preferred choice of response. 
TIA
Bill Murphy
murphy@newton.physics.purdue.edu