Re: [ferret_users] symbols(other than default symbols) for highlighting station data

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

Hi Javeria,
Probably the best way to add symbols is with polygons. You can define polygon shapes of your own, see the POLYGON command in the documentation.

A simple way to plot polygons is with the script polymark.jnl which lets you draw a set of polygons having the same shape.

yes? go/help polymark

This script has several pre-defined polygons to choose from, and they can be optionally filled according to the value of some variable.  Use the /LINE and perhaps the /COLOR= qualifiers on the POLYGON command to outline the polygons and control the color of the outline. And leave off the /PALETTE qualifier to make the polygons hollow. So in the example given at the start of the polymark script you could do things as follows:

yes? use etopo20
yes? shade/x=120:250/y=25s:65n/pal=land_sea/lev=20c rose
yes? let xpts = 180 + 50*cos(2*3.14*i[i=1:50]/60)
yes? let ypts = 15  + 20*sin(2*3.14*i[i=1:50]/60)

yes? go polymark poly/over/line/color=black/nolab xpts,ypts, ,circle,0.8

Making more than one call to polymark with different subsets of points would let you choose different shapes if you like.

A more advanced example of the polymark script can be seen in this demo script, showing how to use polygons to draw vector arrows:

yes? go poly_vec_demo

Javeria Ashraf wrote:

Dear ferret users,

How can I plot symbols(other than default symbols) for highlighting stations on a spatial figure. I have used overlay command for plotting default symbols like square, circle, but it does not allow me to plot for example hollow circle, or hollow square etc.

Thanks in advance,

Javeria Ashraf
Scientific Officer,
Global Change Impact Studies Center,
Islamabad,
Pakistan.