Creates and draws a contour plot over a map.
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl" load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl" function gsn_csm_contour_map ( wks  : graphic, data : numeric, res  : logical ) return_val  : graphic
The data to contour; must be one- or 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 created is returned. The id of the contour plot is returned as an attribute called contour, and the id of the data is returned as an attribute called data. This is useful if you want to use setvalues to change some data or contour options after this function has been called.
This function creates and draws a contour plot over a map on the given workstation. The default projection is cylindrical equidistant, which you can override by setting the mpProjection resource.
If data is two-dimensional, then the leftmost dimension is represented on the Y (latitude) axis, and the rightmost dimension on the X (longitude) axis.
In order for the contours to be overlaid correctly on the map, please see the document "Overlaying data on a map".
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 you see this error when you run your script:
warning:ScalarFieldSetValues: 2d coordinate array sfXArray has an incorrect dimension size: defaulting sfXArray warning:ScalarFieldSetValues: 2d coordinate array sfYArray has an incorrect dimension size: defaulting sfYArray
then try setting gsnAddCyclic to False.
If data has a _FillValue attribute, this value will be used as a missing value.
If the resource cnFillOn is set to True, then the following will happen automatically:
- a labelbar will be automatically added (default horizontal)
- contour line labels will be turned off
- the contour information label will be turned off
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 data 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 data 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: