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Creates and draws a streamline plot over a map, and colors the streamlines using the given scalar field.


load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"  ; This library is automatically loaded
                                                          ; from NCL V6.2.0 onward.
                                                          ; No need for user to explicitly load.

	function gsn_streamline_scalar_map (
		wks     [1] : graphic,  
		u    [*][*] : numeric,  
		v    [*][*] : numeric,  
		data [*][*] : numeric,  
		res     [1] : logical   

	return_val [1] :  graphic



A Workstation identifier. The identifier is one returned either from calling gsn_open_wks or calling create to create a Workstation object.


The u and v data for the streamline plot; must be two-dimensional.


The data for which to color the streamlines by; must be two-dimensional.


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.

Return value

A scalar id of the map plot created is returned. The id of the streamline plot is returned as an attribute called streamline. 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 streamline plot over a map on the given workstation, and colors the streamlines given a scalar field. If u, v, or data have a _FillValue attribute, these values will be used as missing values.

To maximize the area that the streamline plot is drawn in, set the special resource gsnMaximize to True.

In NCL V6.1.0, this function was updated to automatically create a labelbar if stMonoLineColor is set to False.

See Also

gsn_csm_streamline, gsn_csm_streamline_scalar, gsn_csm_streamline_contour_map, gsn_csm_streamline_contour_map_polar, gsn_csm_streamline_map, gsn_csm_streamline_scalar_map, gsn_csm_streamline_scalar_map_polar, gsn_csm_streamline_map_polar, gsn_streamline, gsn_streamline_scalar, gsn_streamline_map, gsn_csm_pres_hgt_streamline

Special gsn resources


For some application examples, see the suite of streamline examples.