National Oceanic and
Atmospheric Administration
United States Department of Commerce

Ferret Polymark Demo

Last modified: Mon, 06/29/2020 - 14:43

Below is an annotated version of the script polymark.jnl:

Note that in PyFerret, similar plots may be drawn using the PLOT/RIBBON command and filled symbols.  The second plot using squares would be duplicated with a PLOT/VS/RIBBON/SYMBOL=boxfill command and /HIGHLIGHT to outline the symbols.  This renders much faster than the outlined polygons drawn in the last example below.

yes? GO basemap x=120:250 Y=25s:65n 20
yes? ribbon/over/vs/SYBMOL=boxfill/HIGHLIGHT/siz=0.15/key/title="SST"  xpts,ypts,sst

 

Make a base map to show the location, and plot (lat,lon,sst) triples to color the locations according to SST on the map.

yes? ! Open demo ship track file with Lat, Lon, and SST
yes? use polydata

yes? ! polymark needs an underlying plot to define scaling
yes? go basemap x=130:250 Y=20:65 20
yes? go polymark poly/over/key/title="SST along track" lon lat sst star 

Use a different style, outlined squares. The available shapes are defined in the script "polyshape" which is called by polymark.jnl

! list the available shapes:

yes? go/help polyshape
 Full path name: /home/users/tmap/ferret/rhel6-x86_64-linux/go/polyshape.jnl
\cancel mode verify
! polyshape.jnl
! ...

! Description: define xpolyshape, ypolyshape variables for polygon fills

!   usage:
!       GO polyshape shape_name

! shape names include:
!    triangle           delta           square
!    diamond            pentagon        hexagon
!    circle             star            plus
!    ex                 rectangle       tallbox
!    hletter            lletter
!    trianglec          deltac          exc
!    rectanglec         tallboxc        fslash
!    bslash             tletter         tupside
!    tleft              tright          vright
!    vleft              rtriangle       ltriangle
!    uright             uleft



yes? go basemap x=130:250 Y=20:65 20
yes? go polymark poly/over/key/line/fill/lev=(1,9,1)/title="Smaller & outline" lon lat sst square .6

Or a pattern fill (Ferret only; Pyferret does not have pattern fill as of version 7)

 ! Use a square in a pattern & outline
yes? go basemap x=130:250 Y=20:65 20
yes? go polymark poly/over/key/pattern=4patterns/palette=black/line/fill/lev=(1,9,2)/title="Using patterns" lon[i=3:37:2] lat[i=3:37:2] sst[i=3:37:2] square 1.75