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Creates and draws a pressure/height plot.


load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_code.ncl"  ; These two libraries are automatically
load "$NCARG_ROOT/lib/ncarg/nclscripts/csm/gsn_csm.ncl"   ; loaded from NCL V6.2.0 onward.
                                                          ; No need for user to explicitly load.

	function gsn_csm_pres_hgt (
		wks     [1] : graphic,  
		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 two-dimensional data to contour. The leftmost dimension must contain a one-dimensional coordinate array of pressure values, and the values must be in the correct units. This is determined by examining the "units" attribute of the coordinate variable. Some accepted units are "hpa", "hPa", "Pa", "pa", "mb", "millibars", etc. If the units attribute doesn't exist or has the wrong value, an error will be issued.

If the pressure levels are in units of "Pa", they will be converted to "hPa" before plotting.


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 contour plot created is returned. The id of the data object is also returned as an attribute called data. 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 pressure/height versus latitude, longitude, or time plot on the given workstation.

If the pressure levels are in units of "Pa", they will be converted to "hPa" before plotting.

The left Y-axis will be labeled with reverse log pressure values, and the right Y-axis with height values in km. The height values are a logarithmic interpolation from Standard Atmosphere of the pressure array. The pressure coordinate array values must lie between 1013.25 mb and 0.010 mb.

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
To turn off the "height" title on the right Y axis, set the special gsnPresHgtHeightLabelOn resource to False.

If you want to turn the labelbar off, set lbLabelBarOn to False.

The special resource gsnAddCyclic will be set to False so that no cyclic point will be added to the data.

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.

See Also

gsn_csm_pres_hgt_vector, gsn_csm_pres_hgt_streamline

gsn_csm_contour, gsn_csm_hov, gsn_csm_time_lat, gsn_csm_lat_time
Special gsn resources


For some application examples, see the suite of pressure/height plots.