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Re: Help with Histogram... [message #45742 is a reply to message #45741]

Wed, 28 September 2005 01:26

peter.albert@gmx.de is currently offline

peter.albert@gmx.de
Messages: 108
Registered: July 2005

Senior Member

Hi again,

assuming that the above assumption is correct, I could propose
something to start with. It's just a start, as there is still one
for-loop, but you can get rid of the ugly where statements:

let's first create some test data:

;I'll use 8 cloud layers, each 300 meters thick:
base = findgen(8) * 1000.
top = base + 300.

;Here is the profile variable:
profile = intarr(60)

; And here come the height levels, just an arbitrary set
; of numbers, unevenly spaced.
; Mind that this array has 61 elements, as you need one upper
; and lower boundary for each layer in "profile"

height_level = [0., exp((findgen(60)-30) / 15.)] * 1300.

; I'll use interpol for finding the correct indices, so we need
; the abscissa values for "height_levels":

x = indgen(61)

; Now, with interpol, we can find those layers of "height_level"
; which will be completely covered by each combination
; of cloud base and top value; using ceil and floor
; is equivalent to the "...GE base[0] AND ... LE top[0] ..."
; in your example:

base_idx = ceil(interpol(x, height_level, base))
top_idx = floor(interpol(x, height_level, top))

; Fine so far, but now I still need a for-loop for filling
; "profile":

for i = 0, 7 do $
if base_idx[i] le top_idx[i] then $
profile[base_idx[i]:top_idx[i]] = 1

Note that the "interpol" way also works if "base" and "top" are not
simple 8-element vectors but rather arrays of size(number_of_profiles,
8). In that case, "base_idx" and "top_idx" are of the same size, but
here the for-loops becomes even more uglier.

Regards,

Peter

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[Message index]

		Re: Help with Histogram... By: MA on Thu, 29 September 2005 11:16
		Re: Help with Histogram... By: peter.albert@gmx.de on Thu, 29 September 2005 03:31
		Re: Help with Histogram... By: MA on Wed, 28 September 2005 11:54
		Re: Help with Histogram... By: MA on Wed, 28 September 2005 09:44
		Re: Help with Histogram... By: btt on Wed, 28 September 2005 05:34
		Re: Help with Histogram... By: peter.albert@gmx.de on Wed, 28 September 2005 01:47
		Re: Help with Histogram... By: peter.albert@gmx.de on Wed, 28 September 2005 01:26
		Re: Help with Histogram... By: peter.albert@gmx.de on Tue, 27 September 2005 23:43

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