National Oceanic and
Atmospheric Administration
United States Department of Commerce

Vector Size

Vector Size

Question:

Can I put an upper limit on vector sizes in Ferret?

Example:

In order to see what is going on in the regions of low wind speed I have to have vector lengths that are fairly small. This causes me to get very large vectors elsewhere.

vector_bad

Solution:

There are lots of ways to skin that particular cat.

Here's one examplewhich generates the figure above and then fixes it by plotting largewind speeds as smaller vectors in bold.

SET DATA monthly_navy_winds
SET REGION/X=100w:20w/Y=80s:20s
VECTOR/ASPECT/L=1/LEN=5/COLOR=BLACK uwnd,vwnd
GO fland 5
VECTOR/ASPECT/L=1/LEN=5/COLOR=BLACK/OVER/NOLAB uwnd,vwnd

!
! Now the fix
!
LET wspd = (uwnd^2+vwnd^2)^0.5
LET hi_threshold = if wspd gt 5 then 1
LET lo_threshold = if wspd le 5 then 1
VECTOR/ASPECT/L=1/LEN=5/title="Zonal Wind, Meridional Wind (m/s)" lo_threshold*uwnd,vwnd
VECTOR/ASPECT/L=1/LEN=20/OVER/COLOR=black/THICK hi_threshold*uwnd,vwnd
GO fland 5
VECTOR/ASPECT/L=1/LEN=5/OVER/COLOR=black/NOLAB lo_threshold*uwnd,vwnd
VECTOR/ASPECT/L=1/LEN=20/OVER/COLOR=black/THICK/NOLAB hi_threshold*uwnd,vwnd

vetctor_with_bold