| Re: Question about storing arrays in pointer array. [message #79590 is a reply to message #79506] |
Fri, 09 March 2012 08:01   |
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Ian[2]
Messages: 7
Registered: March 2012
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Junior Member |
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On Mar 8, 2:35 pm, David Fanning <n...@idlcoyote.com> wrote:
> Ian writes:
>
>> Hello All,
>> I have a question regarding the storage of arrays within arrays. I am
>> attempting to read in 14 data files with 5 vectors of 512 elements. I
>> have attempted two methods:
>
>> ;test attempting to read in variety of data and overplot it in a stack
>> ;without y-axis and single x-axis
>
>> boo=DBLARR(14, 512)
>> ;boo=PTRARR(14)
>> for x = 0,13,1 do begin
>> rdcol, 'iz_diff_rot'+STRCOMPRESS(x,/REMOVE_ALL)
>> +'.dat',p1,p2,p3,p4,p5
>> print, i, " The dat file is: ", 'iz_diff_rot'+STRCOMPRESS(x,/
>> REMOVE_ALL)+'.dat'
>
>> ;attempt 1
>> ;Fills the pointer array with 14 dbl arrays. Use boo=PTR....
>> ; for i=0,13,1 do begin
>> ; boo[i]=PTR_NEW(DBLARR(512))
>> ; p5=boo[i]
>> ; endfor
>> ;endfor
>
>> ;attempt 2
>> ;Creates two dimensional array of 14 columns with 512 elements. Use
>> boo=DBL....
>> for i = 0,13,1 do begin
>> for j = 0,511,1 do begin
>> boo[i,j]=p5[j]
>> endfor
>> print, boo[i,300]
>> endfor
>> endfor
>
>> END
>
>> Attempt one using the pointer array provides 14 arrays but the values
>> are all zero, can anybody give a suggestion on how to store the new p5
>> in boo[i]?
>
> Don't you want something like this:
>
> numFiles = 14
> boo = PtrArr(numFiles)
> FOR j=0,numFiles-1 DO BEGIN
> data = Read_Data(files[j])
> boo[j] = Ptr_New(Reform(data), /No_Copy)
> ENDFOR
>
> Now, each pointer points to an array of 512 columns and 5 rows
> (to make accessing each row faster!).
>
> If you want the 5th vector of the 7th pointer:
>
> thisRow = (*boo[6])[*,4]
>
> Cheers,
>
> David
>
> --
> David Fanning, Ph.D.
> Fanning Software Consulting, Inc.
> Coyote's Guide to IDL Programming:http://www.idlcoyote.com/
> Sepore ma de ni thui. ("Perhaps thou speakest truth.")
>
>
Great! Thank You!
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