| Array index bug.... [message #14328] |
Sun, 21 February 1999 00:00  |
steinhh
Messages: 260
Registered: June 1994
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Senior Member |
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Try this:
data = transpose([[[dist(50)]],[[dist(50)]]],[2,0,1])
help,data
; DATA FLOAT = Array[2, 50, 50]
tvscl,data(0,*,*) ;; Shows the expected image...
But, imagine that you're writing a general program that must
accept arrays with any number of dimensions, and extract data
from the array in (n-1)-dimensional "slices" like the
above. Short of having a CASE statement for every extraction
of data from the array, the way to do this is e.g.:
tvscl,data(0,*,*,*,*) ;; Shows the expected image in this case,
;; works for up to 5 dimensions (though
;; I don't know what TVSCL would say about
;; that!)
Now, IDL *claims* to handle up to 8 dimensions, so one would think
the best thing is to prepare your code for it, e.g.:
tvscl,data(0,*,*,*,*,*,*,*)
The image is *not* what you expect! Clearly something breaks
down with the eighth dimension.....
Another matter is, how do you create e.g., 4-dimensional data
sets with the concatenation style? Lets see:
IDL> help,[1,2]
<Expression> INT = Array[2]
IDL> help,[[1],[2]]
<Expression> INT = Array[1, 2]
IDL> help,[[[1]],[[2]]]
<Expression> INT = Array[1, 1, 2]
IDL> help,[[[[1]]],[[[2]]]]
help,[[[[1]]],[[[2]]]]
^
% Only eight levels of variable concatenation are allowed.
Hmm. Very strange indeed, since I don't even have 8 opening
(or closing) brackets in total, much less anything going to
what *I* would interpret as 8 levels of concatenation....
Regards,
Stein Vidar
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| Re: Array index bug.... [message #16260 is a reply to message #14328] |
Mon, 12 July 1999 00:00  |
luthi
Messages: 20
Registered: March 1999
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Junior Member |
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Gwyn
I tried your code with PV-Wave (6.1, Solaris 2.6) and anything looks ok, until
I use nine subscripts:
print,a(0,*,*,*,*,*,*,*,*)
% Only 8 subscripts allowed.
(btw: Have you tried using parentheses instead of brackets for array indexing,
if this is still allowed in IDL. Probably this could work since both IDL and
PV-Wave once had the same code base... who knows!)
Cheers
Martin
--
============================================================
Martin Luethi Tel. +41 1 632 40 92
Glaciology Section Fax. +41 1 632 11 92
VAW ETH Zuerich
CH-8092 Zuerich mail luthi@vaw.baum.ethz.ch
Switzerland
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