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Re: how to create a LOG array from A to B [message #78995 is a reply to message #78994]

Thu, 12 January 2012 13:50

manodeep@gmail.com
Messages: 33
Registered: June 2006

Member

On Jan 12, 3:41 pm, nata <bernat.puigdomen...@gmail.com> wrote:
> Michael,
>
> Your code works but this is not exactly what I need.
> Using your method I get something like this :
>
> a=1.5
> b=5.45
> N=20
> elev=ALOG10(FINDGEN(N) * (10.^b - 10.^a) / (N - 1.) + 10.^a)
> PLOT, elev, REPLICATE(1,N), YR=[0,2], XR=[a,b], /XLOG, /XS, /YS,
> PSYM=7
>
> And I would like to have all the points equal-spaced on the plot. Do
> you think this is possible ?
> Thank you for your help,
>
> nata

Hi Nata,

As long as A and B are > 0, you can use this:

log_limits = alog10([A,B])
log_binsize = (log_limits[1]-log_limits[0])/(N-1.0)
log_values = findgen(N)*log_binsize + log_limits[0]

values = 10.0d^log_values

HTH,
Manodeep

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[Message index]

		Re: how to create a LOG array from A to B By: Mark Piper on Fri, 13 January 2012 13:32
		Re: how to create a LOG array from A to B By: natha on Thu, 12 January 2012 13:43
		Re: how to create a LOG array from A to B By: manodeep@gmail.com on Thu, 12 January 2012 13:50
		Re: how to create a LOG array from A to B By: natha on Thu, 12 January 2012 13:41
		Re: how to create a LOG array from A to B By: natha on Thu, 12 January 2012 12:05
		Re: how to create a LOG array from A to B By: Michael Galloy on Thu, 12 January 2012 11:52

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