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Re: Reading files with unknown amount of data [message #1355 is a reply to message #1354]

Thu, 04 November 1993 08:09

alans
Messages: 12
Registered: September 1991

Junior Member

I always thought the best approach to the "growing array" problem was to
"cache" the data in an array of a KByte or so. When the "cache" is full,
append to array. So, rewriting the previously posted example program this
way yields:

function read_vl_file, filename

; yes, I *did* test this, but didn't benchmark it...
a = 0.0
i = 0
csize = 1024
cache = fltarr (csize)
openr, lun, filename, /get_lun
while (not eof (lun)) do begin
readf, lun, a
cache(i) = a
i = (i + 1) mod csize
if (i eq 0) then $
if ((size (out))(0) gt 0) then $
out = [temporary (out),cache] else $
out = cache
endwhile

close, lun
free_lun, lun

; grab the rest of the cache.

if (i gt 0) then $
if ((size (out))(0) gt 0) then $
out = [temporary (out),cache(0:i-1)] else $
out = cache(0:i-1)
return, out
end

Anyway, if there are better ways to do this, I'd sure love to hear about
them.
--
Alan J.Stein MIT/Lincoln Laboratory alans@LL.mit.edu

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[Message index]

		Re: Reading files with unknown amount of data By: pendleton on Thu, 04 November 1993 09:46
		Re: Reading files with unknown amount of data By: alans on Thu, 04 November 1993 08:09
		Re: Reading files with unknown amount of data By: zawodny on Thu, 04 November 1993 04:44
		Re: Reading files with unknown amount of data By: brau1231 on Thu, 04 November 1993 03:12
		Re: Reading files with unknown amount of data By: sterne on Thu, 30 September 1993 16:38
		Re: Reading files with unknown amount of data By: zawodny on Thu, 30 September 1993 12:27
		Re: Reading files with unknown amount of data By: pat on Thu, 30 September 1993 10:32
		Re: Reading files with unknown amount of data By: jim on Thu, 30 September 1993 10:47
		Re: Reading files with unknown amount of dat By: oet on Fri, 05 November 1993 00:28

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