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', broken_streamlines=True, *, integration_max_step_scale=1.0, integration_max_error_scale=1.0, num_arrows=1, data=None)[source]#

Draw streamlines of a vector flow.

Parameters:

x, y1D/2D arrays

Evenly spaced strictly increasing arrays to make a grid. If 2D, all rows of x must be equal and all columns of y must be equal; i.e., they must be as if generated by np.meshgrid(x_1d, y_1d).

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 streamlines. 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.

cmap, norm

Data normalization and colormapping parameters for color; only used if color is an array of floats. See imshow for a detailed description.

arrowsizefloat

Scaling factor for the arrow size.

arrowstylestr

Arrow style specification. See FancyArrowPatch.

minlengthfloat

Minimum length of streamline in axes coordinates.

start_points(N, 2) array

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

zorderfloat

The zorder of the streamlines 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.

dataindexable object, optional

If given, the following parameters also accept a string s, which is interpreted as data[s] if s is a key in data:

x, y, u, v, start_points

broken_streamlinesboolean, default: True

If False, forces streamlines to continue until they leave the plot domain. If True, they may be terminated if they come too close to another streamline.

integration_max_step_scalefloat, default: 1.0

Multiplier on the maximum allowable step in the streamline integration routine. A value between zero and one results in a max integration step smaller than the default max step, resulting in more accurate streamlines at the cost of greater computation time; a value greater than one does the converse. Must be greater than zero.

Added in version 3.11.

integration_max_error_scalefloat, default: 1.0

Multiplier on the maximum allowable error in the streamline integration routine. A value between zero and one results in a tighter max integration error than the default max error, resulting in more accurate streamlines at the cost of greater computation time; a value greater than one does the converse. Must be greater than zero.

Added in version 3.11.

num_arrowsint

Number of arrows per streamline. The arrows are spaced equally along the steps each streamline takes. Note that this can be different to being spaced equally along the distance of the streamline.

Returns:

StreamplotSet

Container object with attributes

• lines: LineCollection of streamlines

• arrows: PatchCollection containing FancyArrowPatch objects representing the arrows half-way along streamlines.

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

This is the pyplot wrapper for axes.Axes.streamplot.

Examples using matplotlib.pyplot.streamplot#

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Streamplot

Streamplot