Re: [ferret_users] Plotting curvilinear vectors

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

Dear Steve,

I forgot that the whole thing that precipitated this discussion is that you wanted a scaling vector key.  So try this script which uses Ansley's poly_arrow_key:

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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 = { `360-75`, `360-70`, `360-65` }

let lat = { 25, 30, 35 }

let temperature = { 10, 20, 30 }

let fill_values = ysequence( temperature )

let rt2 = 2^0.5

let u = { `100/rt2`, 100,   0 }

let v = { `100/rt2`,   0, 100 }

let vel_scl = 50

go mp_poly_vectors lon lat u v `vel_scl` "arrow"

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

! Draw scaling vector

go poly_arrow_key "Velocity" `vel_scl` red

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The result should look like the attached gif:

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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.