Re: [ferret_users] Plotting curvilinear vectors

["E. D. (Ned) Cokelet" <Edward.D.Cokelet@xxxxxxxx>]

Stephen,

You need to set up the Ferret map projection variables called MP_... before mp_poly_vectors will work properly.  The mp_poly_vectors variables rely on values calculated in the map projection scripts.  Try this script:

*************************************************************************

use etopo5

define grid/like=rose map_grid

set grid map_grid

set region/x=80w:50w/y=20n:40n

go mp_mercator 30 -65

go mp_aspect

fill/levels=(0,10000,10000)/pal=grey/nokey/noaxis/nolabel rose[g=map_grid],x_page,y_page

go mp_graticule `360-80` `360-50` 5.0 20 40 5.0 1

let lon = { `360-72`, `360-68` }

let lat = { 26, 32 }

let temperature = { 10, 20 }

let fill_values = ysequence( temperature )

let u = { 5, 10 }

let v = { 5, 40 }

go mp_poly_vectors lon lat u v 10 "arrow"

polygon/over/nolabel/key/noaxes mp_x_arrow, mp_y_arrow, fill_values[j=1:`num_vectors`]

------------------------------------------------------------------------------------------

Edward D. (Ned) Cokelet, Ph.D. Oceanographer

NOAA/PMEL off:  (206) 526-6820

7600 Sand Point Way NE fax: (206) 526-6485

Seattle, WA 98115-6439

Edward.D.Cokelet@noaa.gov

The contents of this message are mine personally and do not necessarily reflect any position of the Government or the National Oceanic and Atmospheric Administration.