iraf.net

Hi Josh,On Mon, 26 Sep 2005, Joshua Jacob Turner wrote:> I have a question that has been giving me some trouble. I wrote a
> script to compare two files, one is a normal file, and one is a set of
> 50 (3D file). I thought I would be able to compare the 3D one as
> file[x,y,*] in the normal way, so it was go through and just read all
> 50, but it doesn't. I haven't been able to get a 'for' loop to work in
> the script either. I thought it would be easiest then to just turn
> this 3D file into a @-list, but the script won't read that either. Do
> you have any ideas or advice that might be helpful? Thanks, I'm a little confused by your use of the word 'file' and the
*image* section syntax in your message. What exactly are you trying to
compare and how (i.e. are you trying to find the difference between one
image and the 50 bands of a second data cube?)?
If you're trying to loop through the bands then something like
for (i=1; i <= 50; i=i+1) {
imarith ("im001", "-", "cube[*,*," // i // "]", "out" // i)
}will loop over all 50 bands, subtracting the section "cube[*,*,<num>]"
from "im001" and writing the results to "out<num>" where <num> is the
index number.
Using you "file[x,y,*]" section syntax implies you're looping
over every pixel in (x,y) and extracts a 1-D section 50 pixels deep,
i.e. all 50 bands at the coords (x,y). Is this what you wanted? If
you just want to split the 3-D image into 2-D slices, see the IMSLICE
task, you can make an @-file of the resulting image list.
Hope this helps. If you still have questions please supply more
details about what you are trying to do.Cheers,
-Mike