comp.lang.idl-pvwave archive: archive

Home » Public Forums » archive » Re: Speeding up I/O

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: Speeding up I/O [message #38539 is a reply to message #38534]

Tue, 16 March 2004 15:53

R.G. Stockwell
Messages: 363
Registered: July 1999

Senior Member

"Ken Knapp" <Ken.Knapp@REMOVEnoaa.gov> wrote in message news:c37rd7$n9s$1@news.nems.noaa.gov...
> Are there any tricks to speed up I/O?
> Situation: I have 1.2 TB of data to process. The following is a typical
> read statement:
> in = {header:bytarr(128),scan:intarr(1250)}
> image = replicate(in,1250)
> openr,1,file
> readu,1,image
> close,1
> Then I process the image and output something. The slow part is in the
> readu [I used profiler to find that readu IS slowing me down, the
> computations are only a fraction of the read time].
> Any suggestions on how to speed it up?
> Tricks to make the computer find files faster?
> Would Fortran/C be faster?
>
> Any help is greatly appreciated.
> -Ken
> --
> ***** to reply remove the _REMOVE_ *****
>
> Ken Knapp Ken.Knapp@_REMOVE_noaa.gov
> Remote Sensing and Applications Division
> National Climatic Data Center
> 151 Patton Ave
> Asheville, NC 28806
> 828-271-4339 (voice) 828-271-4328 (fax)
>

Just curious, does it take longer than about 0.02 seconds to read in the data?
for instance...

t = systime(1)
openr,1,file
readu,1,image
close,1
print,'read time', systime(1)-t

Cheers,
bob

Report message to a moderator

[Message index]

		Re: Speeding up I/O By: Rick Towler on Wed, 17 March 2004 08:49
		Re: Speeding up I/O By: Ken Knapp on Wed, 17 March 2004 05:19
		Re: Speeding up I/O By: schaa on Wed, 17 March 2004 00:41
		Re: Speeding up I/O By: marc schellens[1] on Tue, 16 March 2004 19:09
		Re: Speeding up I/O By: R.G. Stockwell on Tue, 16 March 2004 15:53

Previous Topic:	ENVI: How to remove vector layer from the list of available vectors programmatically?
Next Topic:	Re: dynamically change the layout of widget

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Oct 11 03:53:11 PDT 2025

Total time taken to generate the page: 0.32217 seconds