Re: [ferret_users] speed up PLOT/VS x,y?

["William S. Kessler" <William.S.Kessler@xxxxxxxx>]

The amount of time it takes to plot is not just the calculation, but  
the time it takes to throw the pixels onto the screen. That is  
inherently going to be a lot of time for 500,000 points (times as many  
vectors as have to be drawn for each point). (Of course, I'll bet you  
very many of those points are overlaying others, so there is much more  
information on such a plot than can be seen). You can get maximum speed  
by choosing your plot symbol to be as simple as possible (05 or 07 are  
single lines, 01 and 03 are plus or mult signs, 19 is a triangle):

plot/vs/sym=nn v1,v2

See the list of plot marks at:

http://ferret.pmel.noaa.gov/Ferret/Documentation/Users_Guide/ 
pplus_symbol_fonts.html

Billy K

On Oct 5, 2005, at 1:53 AM, hengkek@nus.edu.sg wrote:

> Is there any way (tricks) to speed up "PLOT/VS X,Y" for 500,000 points?
>
>  name     title                  I         J         K         L
> PT       potential temperature  1:133     1:199     1:20      1:21
>
> When I do "PLOT/VS/L=1 PT[d=1],PT[d=2]" it takes about 1 min 20 secs  
> to complete.
> A smaller subset: "PLOT/VS/L=1/K=1 PT[d=1],PT[d=2]" takes about 3 secs.
> But "SHADE/L=1/K=1 PT[d=1]" takes less than 1 sec for the same number  
> of points.
>
> -Kek
>         NOAA/PMEL TMAP
>         FERRET v5.70
>         Linux(g77) 2.4.18 - 06/30/04
>          5-Oct-05 16:37
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
William S. Kessler
NOAA / Pacific Marine Environmental Laboratory
7600 Sand Point Way NE
Seattle WA 98115 USA

william.s.kessler@noaa.gov
Tel: 206-526-6221
Fax: 206-526-6744
Home page: http://www.pmel.noaa.gov/~kessler