Re: log-depth-axis contour plot

[Rodrigo Caballero Augi <rca@xxxxxxxxx>]

Hi Patrick,

Yes, I came accross the same problem when trying to plot
wavenumber-frequency spectra, and did not come up with a solution.
I think this is one for the gurus.
 
_____				

Rodrigo Caballero Augi  |  http://rodrigo.gfy.ku.dk



On Mon, 2 Aug 1999, Patrick Joeckel wrote:

> Dear Ferret Users,
> 
> On Fri, 19 Feb 1999 13:38:47 +0100 (MET) 
> Rodrigo Caballero Augi gave the following example to do log-log contour 
> plots and achieve a proper log-axis, i.e.
> 'the contours rescaled to the log axes *and* the "ppl axtype 2,2"-style 
> tic marks - that is, with the ticks unevenly spaced'.
> 
> However, if I try this with a /DEPTH-defined axis,
> ferret exits with this messages :
> YLO,YHI                                   on DEC-Alpha (Version 5) 
> 
> STOP: YLO,YHI                         
> Warning: Floating underflow occurred      on a Linux-PC (Version 5)
> 
> Does anybody have a solution ?
> 
> Thank you for your help !
> 
> Sincerely,
> 
>                Patrick Joeckel
> 
> 
> here is the above cited suggestion for non /DEPTH-defined axes:
> !!!!!!
>  ! 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/10)+y/100    ! some made up data
>  
>  ! plot untransformed data in the upper plot
>  set view upper
>  ppl axtype 1,1
>  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
>  ppl axtype 2,1
>  contour a[gx=xlog@asn]*0
>  ppl axtype 1,1
>  contour/over/pen=1/nolab a[gx=xlog@asn]
> !!!! end of example
> 
> ---------------------------------------------------------------
> Patrick Joeckel
> Max Planck Institute for Chemistry
> Joh.-J. Becher Weg 27         
> 55128 Mainz                   phone:++49-6131-305452      
> Germany                       fax  :++49-6131-305436     
>                              e-mail:joeckel@mpch-mainz.mpg.de
>                          http://www.mpch-mainz.mpg.de/~joeckel
> ---------------------------------------------------------------
>