array subtraction [message #63346] |
Wed, 05 November 2008 07:25 |
julia.walterspiel
Messages: 35 Registered: July 2008
|
Member |
|
|
hey guys
SOS call from the newbie:
I've got two data arrays, one of length 134 (=a), the other of length
75 (=b) with monthly cloud cover data from modis terra and aqua.
Data from Terra starts feb 2000, data from Aqua starts july 2002.
I want to calculate and plot the difference in cloud cover for each
month from Terra and Aqua. so far so good.
the two data arrays are "connected" by two (separate) time arrays c
(for Terra, feb 2000 - now) and d (for Aqua july 2002 - now).
that means, my data array "b" starts only somewhere at index so-and-so
of "a" (not sure where exactly).
Now, how can I tell IDL to subtract the two arrays at the right point,
meaning subtract the terra-value on july 2002 from the aqua value on
the same date?
I'm sure everyone of you can do that with both eyes closed and it
can't be difficult but I couldn't find any help online.
thanks!
juls
|
|
|