Re: log-log contour

[Steve Hankin <hankin@xxxxxxxxxxxxx>]

Hi Rodrigo,

The LOG axis transforms (PPL AXTYPE) are not applicable to the 2D plots
(CONTOUR,VECTOR,SHADE, and FILL).

Here is another way (by example) to achieve a similar result:

 ! suppose you have some data on a grid x=1:100:1, y=1:100:1
 define axis/x=1:100:1 xax
 define axis/y=1:100:1 yax
 define grid/x=xax/y=yax gg
 set grid gg
 let a = LOG(x/8)+y/100    ! some made up data
 
 ! plot untransformed data in the upper plot
 set view upper
 contour a
 
 ! define a new axis with the LOG transform of the X coordinates
 define axis/from/name=xlog/x LOG(x)
 
 ! plot LOG-transformed data in the lower plot
 set view lower
 contour a[gx=xlog@asn]


Hope this helps.

	Happy Ferreting - steve

======================================


Rodrigo Caballero Augi wrote:
> 
> Hello,
> 
> I'm having trouble making contour plots where the axes are log-log, as in
> 
> ppl axtype 2,2
> contour my_data
> 
> this produces log-log axes, but the actual contour plot is identical to
> that in a linear-linear plot - that is, the contour lines are not rescaled
> to the log-log axes. Any help would be appreciated.
> 
> Thanks,
> Rodrigo
> 
> ---
> 
> Rodrigo Caballero Augi
> DCESS, Juliane Maries Vej 30, DK-2100 Copenhagen O, Denmark.
> tel: +45 35320565 | fax: +45 35365357 | home: +45 35836487
> rca@gfy.ku.dk | http://rodrigo.gfy.ku.dk

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