Re: FOR statement

[JD Smith <jdsmith(at)astro.cornell.edu>]

Eli Beckerman wrote:
> 
> Hey,
> 
> I just tried running a FOR loop in the hopes
> of incrementing the variable "i" by steps of 0.25 as follows:
> 
> radius=fltarr(1000)
> FOR i=0.0, 100.0, 0.25 DO BEGIN
> 
>   radius(i)=i
> 
> ENDFOR
> 
> And what I end up with is an array that starts
> with the value 0.75 and is incremented by steps of 1.
> 
> I'm following the convention of the FOR statement as
> presented in IDL's online help. What am I doing wrong?!

Indexing an array with a floating point number.

try:

FOR i=0.0, 100.0, 0.25 DO BEGIN radius[4*i]=i

or even better:

radius=findgen(401)/4.

JD