comp.lang.idl-pvwave archive: archive » Re: reading an ascii file efficiently

Home » Public Forums » archive » Re: reading an ascii file efficiently

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

Re: reading an ascii file efficiently [message #68915 is a reply to message #68913]

Fri, 27 November 2009 10:39

jeanh
Messages: 79
Registered: November 2009

Member

nata wrote:
> Hi guys,
>
> I'm reading an ascii file and I can do that using different methods.
> Now, I'm trying to use the most efficiently method. I do something
> like this:
>
> lines=FILE_LINES(file)
> rr=STRARR(lines)
> OPENR, lun, file, /GET_LUN
> READF, lun, rr
> FREE_LUN, lun
>
> Now i have all the information in rr variable. Each line have the
> following information:
> 280 , 0 , 280 , 0 , -58.085 , -32.616 , -32.000
> or
> 15 , 1 , 15 , 1 , -60.908 , -32.603 , -32.000
>
> And I need to return only the last value, so -32.000. I can use
> STRSPLIT or STRMID with STRPOS but is not efficient so I'm trying to
> use READS for each line. Something like this:
>
> aux=0.
> result=FLTARR(lines)
> FOR i=0l, lines-1 DO BEGIN
> READS, rr[i], aux, aux, aux, aux, aux, aux, aux,
> FORMAT='(F0,",",F0,",",F0,",",F0,",",F0,",",F0,", ",F0,",",)'
> result[i]=aux
> ENDFOR
>
> You can see that I don't know how to use the FORMAT keyword properly
> so maybe you have an idea of how to skip the first 6 values.
> Using a template, strsplit, etc. I found that this is the most
> efficient way to read this *@#$* file.
>
> Thanks if you can help me with this format or if you have a
> suggestion.
>
> nata
>

what about reading your data in a float array directly?
data = fltarr(nbCol,nbLines)
readf,lun,data

dataToKeep = data[nbCol-1,*]

Jean

Report message to a moderator

[Message index]

		Re: reading an ascii file efficiently By: jeanh on Mon, 30 November 2009 06:50
		Re: reading an ascii file efficiently By: natha on Mon, 30 November 2009 06:39
		Re: reading an ascii file efficiently By: David Fanning on Sat, 28 November 2009 11:00
		Re: reading an ascii file efficiently By: penteado on Fri, 27 November 2009 21:04
		Re: reading an ascii file efficiently By: David Fanning on Fri, 27 November 2009 20:56
		Re: reading an ascii file efficiently By: penteado on Fri, 27 November 2009 19:58
		Re: reading an ascii file efficiently By: Heinz Stege on Fri, 27 November 2009 19:27
		Re: reading an ascii file efficiently By: Heinz Stege on Fri, 27 November 2009 19:16
		Re: reading an ascii file efficiently By: penteado on Fri, 27 November 2009 14:45
		Re: reading an ascii file efficiently By: natha on Fri, 27 November 2009 11:02
		Re: reading an ascii file efficiently By: jeanh on Fri, 27 November 2009 10:39
		Re: reading an ascii file efficiently By: b_gom on Fri, 27 November 2009 10:34

Previous Topic:	Re: Larger arrays or more dimensions?
Next Topic:	SHAPEFILE changes in IDL7.1?

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Fri Oct 10 05:43:48 PDT 2025

Total time taken to generate the page: 0.80232 seconds