Re: [ferret_users] How to use barb with Ferret

[Ansley Manke <ansley.b.manke@xxxxxxxx>]

Hi Ashranf,
I don't know grads so I can't say exactly what the equivalent Ferret 
command might be.  It looks like this commad is skipping some data and 
plotting vectors.  The Ferret command VECTOR/XSKIP/YSKIP will do this.

Ferret does not have the option of removing the arrows on vectors (is 
that what is meant by a barb plot?), but there is a script called 
poly_vectors.jnl that draws vectors using polygons, and using that 
script you can choose not to draw the arrows.  Please run the demo script

  yes? go poly_vec_demo

For examples of how to call this script.  Read the text as the demo 
runs; there are some variables to define before running 
poly_vectors.jnl.  There is also a script vector_demo.jnl which shows a 
variety of ways to draw vector plots with the standard VECTOR command.

To set the line type for contour lines, you need to use settings on the 
/LEVELS qualifier. The LINE sets the line type to a solid line for the 
contour levels that are given just after it.  Normally the negative 
contour levels would be dashed, so this comand resets them to a thin 
solid line

  yes? use etopo120
  yes? contour/lev="(-4000,4000,1000)LINE(-4000,-1000,1000)" rose

Once again, there is a demo script for this topic:

  yes? go custom_contour_demo.jnl


There are a number of Ferret demonstrations. Some are available as 
on-line demos with graphics and text, others are just scripts.  They are 
all listed at

  http://www.ferret.noaa.gov/Ferret/on_line_demonstrations.html


Ansley



Ashraf Zakey wrote:

> Hello everyone,
>
>    I would like to draw wind speed and direction
> using barb. For example in Grads we can do it as:
>
> set gxout barb
> d skip(u*2,6,6);v*2
>
> How we can do it in Ferret?
>
> -Also, I noticed that the negative contour in Ferret
> it take dot style , How I can force this contouro
> be solid style.
>
>      Looking for your kind reply
>
> All the best
>
> Ashraf
>
>
> ''~``
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> |           Ashraf Saber Zakey                        |
> |           Department of Chemistry                   |
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