Re: overlay shaded areas

[rredler@xxxxxxxxxxxxxxxxxxxx]

On Fri, 6 Sep 1996, Jose Edson Pereira wrote:

> Hello,
> 
>    I'm using ferret to plot sequential contours and vectors in a ocean 
> area, I'd like to overlay in these maps a personal shaded land area (with  
> similar effect as the command " go land "). The reason is that I'm working  
> with  resolution arond 30 sec (degrees), and the best resolution that 
> I can get  with ferret is 5 min. 
>    Coud you help me? 
> 
>    The ferret commands that I'm using:
> 
> define axis/x=1:77:1 xa
> define axis/y=1:166:1 ya
> define axis/t=1:40:1 ta
> define grid/x=xa/y=ya/t=ta grida
> file/var="eta,u,v"/grid=grida ferret.out
> repeat/t=1:40 (shade/levels=(-4,4,0.5) eta; vector/length=1/overlay u,v;
>                            contour/levels="(0,0,1) dark(0)"/overlay eta)
> 

Hallo Jose,

I assume that values on your topography are set to some missing value.
In this case the following two line should give you the desired result:

let topo=missing(u,5000)
shade/overlay/level=(5000:5000:1)/nolabel/nokey/pal=grey topo[k=1]

with temp being a 3-d array, e.g. your variable u. The first line than
defines are new variable topo that is set to 5000 at all indices where
u has a missing value. With the second line the topography for any
level - in this case k=1 - can be overlayed on your plot.

Hopefully this helps

Rene