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Ngl.streamline_scalar

Creates and draws a streamline plot with the streamlines colored by a scalar field.

Available in version 1.3.0 or later.

Prototype

st = Ngl.streamline_scalar(wks, u, v, data, res=None)

Arguments

wks

The identifier returned from calling Ngl.open_wks.

u, v

The U and V components of the streamlines. u and v should be two-dimensional NumPy array or NumPy masked arrays (dimensioned ny x nx).

data

The scalar data field for coloring the streamlines (dimensioned ny x nx).

res=None

An (optional) instance of the Resources class having PyNGL resources as attributes.

Description

This function creates and draws a streamlines, colored by a scalar field, on the given workstation and advances the frame. Plot options can be set via the res variable.

If coordinate values for the X and Y axes are not available, then index values will be used on the axes.

If axes coordinate information is available, then set the vfXArray (sfXArray) resource to the one-dimensional NumPy array (of length nx) that represents the X axis, and vfYArray (sfYArray) to the one-dimensional NumPy array (of length ny) that represents the Y axis. Or, you can optionally send some end point values via the resources vfXCStartV (sfXCStartV), vfXCEndV (sfXCEndV), vfYCStartV (sfYCStartV), vfYCEndV (sfYCEndV) resources.

As of version 1.3.0, if u, v, and/or data are masked arrays, then any values equal to the corresponding fill values will not be plotted. If u, v, and/or data are not masked arrays and they contain missing values, then set the resources vfMissingUValueV, vfMissingVValueV, and/or sfMissingValueV to these values.

Note that PyNGL internally sets some resources for you, depending on how other resources are set. See the list of default settings for more information.

Ngl.streamline_scalar

Prototype

Arguments

Description

See Also