Re: Logarithmic Vectors

[Andrew Wittenberg <atw@xxxxxxxxxxxxx>]

On Sat, 25 Jan 2003, Dixon, Jeff USA wrote:
> I am trying to place logarithmic scaled vectors of ocean currents on the
> same plot but not sure how.  The idea is to eliminate the issue of
> extremely large vectors in straits or coastal regions where there are
> comparatively high velocities and open ocean areas where average
> velocities are much lower - but all in the same set region using scalar
> velocity vectors.  Any assistance is greatly appreciated - thanks.

Hi Jeff,

You could try something like

let wspd = (u^2 + v^2)^.5
let wspd_min = wspd[x=@min,y=@min,t=@min]
let scale = log(wspd/wspd_min)
let u_unit = u/wspd
let v_unit = v/wspd

vector scale*u_unit, scale*v_unit

Andrew

+--------------------------------------------------------+
|   Dr. Andrew T. Wittenberg   |        GFDL/NOAA        |
|      atw@gfdl.noaa.gov       |      Princeton, NJ      |
+--------------------------------------------------------+