| Re: More For Loops [message #19676] |
Thu, 13 April 2000 00:00  |
Craig Markwardt
Messages: 1869
Registered: November 1996
|
Senior Member |
|
|
Craig Markwardt <craigmnet@cow.physics.wisc.edu> writes:
> majewski@cygnus.uwa.edu.au_stralia writes:
...
>> for i = 0, (DATA_size[0]/2)-1 do begin
>> for j = 0, DATA_size[1]-1 do begin
>> Data_sets_ev[i,j] = my_data[(2*i),(2*j)]
>> Data_sets_od[i,j] = my_data[(2*i),(2*j+1)]
>> endfor
>> endfor
...
>
> Keep in mind that a (2M) x N array can be thought of as a 2 x M x N
> array -- or an M x N array of pairs. IDL can reform the first kind of
> array into the second, and then it's a simple matter of extracting
> what you want. The "_ev" is the first of each pair, the "_od" is the
> second.
>
> my_data = reform(my_data, 2, x_data/2, y_data, /overwrite)
>
> data_sets_ev = my_data[0,*,*]
> data_sets_od = my_data[1,*,*]
Ah, replying to myself. I must be getting older.
I see now that I didn't understand the layout of your original array.
Your my_data is really a (2*M*2) x N array. That is, the even and odd
rows are interleaved. This is still no problem. The revised form is:
my_data = reform(my_data, 2, x_data/4, 2, y_data, /overwrite)
; pair row pair of rows array
data_sets_ev = my_data[0,*,0,*]
data_sets_od = my_data[0,*,1,*]
In this case it appears that you are only interested in the first of
each pair of elements, hence the [0,...].
Craig
--
------------------------------------------------------------ --------------
Craig B. Markwardt, Ph.D. EMAIL: craigmnet@cow.physics.wisc.edu
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
------------------------------------------------------------ --------------
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
