Hi Ashraf,
There are a couple of different ways to do this. There is a script,
multi_variable_demo, which shows how to use some tools written for
this. There can sometimes be problems with these scripts when used
with time series; the line sample that they draw for a key may not be
drawn.
Another way, when you want one scale on the left and another on the
right, but with the same horizontal axis, is to define two viewports,
exactly the same size and location, and draw each variable in its own
viewport. The plots are drawn on top of each other, creating an overlay
effect. With this method, you have to do some work to get the
labelling correct: The unlabel commands remove the Longitude and
Latitude labels that are automatically placed in the upper left; and
the /TITLE qualifiers set a general title that applies to both plots.
yes? use coads_climatology
yes? let aa = sst[x=180,y=0]
yes? let bb = sst[x=180,y=40]
yes? define view/x=0:1/y=0:1 aaview
yes? define view/x=0:1/y=0:1 bbview
yes? set view aaview
yes? plot/axes=1,1,1,0/color=red/title="SST"/set aa
yes? ppl ylab "Deg C (180,0)"
yes? go unlabel 4
yes? go unlabel 5
yes? ppl plot
yes? set view bbview
yes? plot/axes=1,1,0,1/color=blue/title=" "/set bb
yes? ppl ylab "Deg C (180,40)"
yes? go unlabel 4
yes? go unlabel 5
yes? ppl plot
Ashraf Zakey wrote:
Hi, Ansley:
Thank you very much for your kind reply and for
your help. As matter of fact, I'm new user for Ferret
and I found that it is very interesting visualization
package. I think my contour line looking good now.
One more question please, I have netcdf data and I
would like to select one grid point "latitude,
longitude" and on one panel I would like to draw two
variables each of them has different scale. How I can
do that? Is there any possibility to draw and backward
trajectory?
Thanks one more for your kind help
All the best
Ashraf
--- Ansley Manke <ansley.b.manke@noaa.gov> wrote:
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 |
| Atmospheric Science group |
| Universty of Gothenburg |
| SE 412 96 Gothenbrg |
| Sweden |
| e-mail: zakey@chem.gu.se |
| ashraf_saber123@yahoo.com |
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