Streamline Plot Templatesgsn_csm_streamline
Added in NCL V6.3.0:
Added in NCL V6.3.0:
gsn_csm_streamline_map_ce is the plot interface that draws streamlines on a cylindrical equidistant projection.
stArrowLengthF = 0.004, Changes the size of the arrows
stMinArrowSpacingF = 0.004, Changes the arrow spacing
stArrowStride = 3, indicates that arrows are placed every third grid point. The default is 2.
stLineThicknessF = 1.5, Changes the line thickness
stLineColor = "orange",changes the streamline color
gsn_csm_streamline_map_polar is the plot interface that draws a streamline plot over a polar plot.
stArrowLengthF = 0.008,
controls the length of the directional arrows. The default is
stLengthCheckCount = 15, controls how frequently a new streamline is started. The value is in terms of an internal NCL loop that calculates new starts. The default is 35.
stArrowStride = 1, Controls in which grid cells an arrow head is draw. The default is every other grid cell.
stLineStartStride = 1, Controls which grid points are allowed to start new streamlines. The default is 2, which is every other grid cell.
stMinArrowSpacingF = 0.035, controls the distance between drawn arrows. The default is 0.0, which could draw arrows right on top of each other.
stStepSizeF= 0.001, Controls the basic step size used to create the streamline. The default is dynamic.
The following two resources on the ones that you will really have to tweak depending upon the field you are plotting.
gsn_csm_streamline is the plot interface that draws a streamline plot without a map.
gsn_csm_streamline_contour_map_ce is the plot interface that draws a streamline plot over a contour plot.
gsn_csm_streamline_contour_map_polar is the plot interface that draws a streamline plot over a contour plot with a polar projection.
The "stream_8.ncl" script uses a single interface, gsn_csm_pres_hgt_streamline, to draw a streamline plot over a press/height plot.
The "stream_overlay_8.ncl" script uses a 5-step process to create the same plot:
The 5-step process is more work, but can allow you more flexibility if you need to overlay other plots.
Alan Brammer of the University at Albany contributed the initial version of this example and the code necessary to get gsn_panel to recognize streamline plots and create a labelbar.
Note: you need NCL version 6.3.0 to run this example.
Alan Brammer of the University at Albany contributed the initial version of this example and contributed the gsn_csm_streamline_scalar_xxx functions which we added to NCL Version 6.3.0.