matplotlib.pyplot.streamplot

matplotlib.pyplot.streamplot(x, y, u, v, density=1, linewidth=None, color=None, cmap=None, norm=None, arrowsize=1, arrowstyle='-|>', minlength=0.1, transform=None, zorder=None, start_points=None, maxlength=4.0, integration_direction='both', *, data=None)

Draw streamlines of a vector flow.

Parameters:

x, y1D arrays

An evenly spaced grid.

u, v2D arrays

x and y-velocities. The number of rows and columns must match the length of y and x, respectively.

densityfloat or (float, float)

Controls the closeness of streamlines. When density = 1, the domain is divided into a 30x30 grid. density linearly scales this grid. Each cell in the grid can have, at most, one traversing streamline. For different densities in each direction, use a tuple (density_x, density_y).

linewidthfloat or 2D array

The width of the stream lines. With a 2D array the line width can be varied across the grid. The array must have the same shape as u and v.

colorcolor or 2D array

The streamline color. If given an array, its values are converted to colors using cmap and norm. The array must have the same shape as u and v.

cmapColormap

Colormap used to plot streamlines and arrows. This is only used if color is an array.

normNormalize

Normalize object used to scale luminance data to 0, 1. If None, stretch (min, max) to (0, 1). This is only used if color is an array.

arrowsizefloat

Scaling factor for the arrow size.

arrowstylestr

Arrow style specification. See FancyArrowPatch.

minlengthfloat

Minimum length of streamline in axes coordinates.

start_pointsNx2 array

Coordinates of starting points for the streamlines in data coordinates (the same coordinates as the x and y arrays).

zorderint

The zorder of the stream lines and arrows. Artists with lower zorder values are drawn first.

maxlengthfloat

Maximum length of streamline in axes coordinates.

integration_direction{'forward', 'backward', 'both'}, default: 'both'

Integrate the streamline in forward, backward or both directions.

Returns:

StreamplotSet

Container object with attributes

• lines: LineCollection of streamlines
• arrows: PatchCollection containing FancyArrowPatch objects representing the arrows half-way along stream lines.

This container will probably change in the future to allow changes to the colormap, alpha, etc. for both lines and arrows, but these changes should be backward compatible.

Notes

Note

In addition to the above described arguments, this function can take a data keyword argument. If such a data argument is given, the following arguments can also be string s, which is interpreted as data[s] (unless this raises an exception): x, y, u, v, start_points.

Objects passed as data must support item access (data[s]) and membership test (s in data).

Examples using matplotlib.pyplot.streamplot

Streamplot

Sample plots in Matplotlib