Creates and draws a vector plot over a map, and uses a scalar field to draw a separate contour plot or color the vectors.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" function gsn_csm_vector_scalar_map ( wks  : graphic, u [*][*] : numeric, v [*][*] : numeric, data [*][*] : numeric, res  : logical ) return_val  : graphic
The u and v data for the vector plot; must be two-dimensional.data
The data for which to create a separate contour plot or color the vectors by; must be two-dimensional.res
A variable containing an optional list of plot resources, attached as attributes. Set to True if you want the attached attributes to be applied, and False if you either don't have any resources to set, or you don't want the resources applied.
A scalar id of the map plot created is returned. The id of the vector plot is returned as an attribute called vector. The id of the data object is returned as an attribute called vfdata, and the id of the scalar data object is returned as an attribute called sfdata. This is useful if you want to use setvalues to change some data options after this function has been called.
This function creates and draws a vector plot over a map on the given workstation. By default, the scalar field is used to color the vectors, unless the special resource gsnScalarContour is set to True, then a separate contour plot is created.
In order for the vectors and contours to be overlaid correctly on the map, please see the document "Overlaying data on a map".
The default projection is a cylindrical equidistant, which you can override by setting the mpProjection resource.
The special resource gsnAddCyclic will be set to True so that a cyclic point will be added to the data. Set this resource to False if your data is not cyclic, or if you have already added the cyclic point in another fashion.
If u, v, or data have a _FillValue attribute, these values will be used as missing values.
For the map, the following will happen automatically:
- the continents will be colored gray
- the continental outlines will be turned off
- the latitude/longitude locations will be labeled (cylindrical equidistant and polar stereographic maps only)
- the tickmarks will point outward (cylindrical equidistant map only)
If u has an attribute called "long_name", and gsnLeftString hasn't explicitly been set, then the value of this attribute is used for the left string title.
If u has an attribute called "units", and gsnRightString hasn't explicitly been set, then the value of this attribute is used for the right string title.
To maximize the area that the plot is drawn in, set the special resource gsnMaximize to True.
For some application examples, see: