Re: reading dem

[Craig Markwardt <craigmnet(at)cow.physics.wisc.edu>]

Sylvain Carette <sylvainc@total.net> writes:

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> Well it didnt work.. :-(
> I got:
> % Input line is too long for input buffer of 32767 characters.
> % READF: Error encountered reading from file. Unit: 100, File:
> D:\gis\DEM250\montrealw.dem
> 
> Now I'm stuck... is there a way to make readf read only no more than 32767
> char?

Okay, so you can read <31 1024-blocks at a time, unformatted.  Then
you convert to a string and use reads.

ii = 0L
bb = bytarr(1024L*31) && ll = lonarr(170L*31)
while ii LT nvals do begin
  readu, lun, bb           ;; Read blocks
  reads, string(bb), ll    ;; Change to a string and parse into LONGs
  im(ii:ii+170-1) = ll     ;; Insert into image array
  ii = ii + n_elements(ll) ;; Advance array index
end

This doesn't handle the case of the first block, which only has 135
elements, but you should get the idea.  Now why not try a little
experimentation on your own...

Good luck,
Craig

P.S. I used a long integer because the values are defined in the spec
as INTEGER*4.

-- 
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Craig B. Markwardt, Ph.D.         EMAIL:    craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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