matplotlib.streamplot

Streamline plotting for 2D vector fields.

Functions

matplotlib.streamplot.streamplot(axes, 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)

Draw streamlines of a vector flow.

Parameters:

  • x (1D/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).

  • y (1D/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 (2D arrays) – x and y-velocities. The number of rows and columns must match the length of y and x, respectively.

  • v (2D arrays) – x and y-velocities. The number of rows and columns must match the length of y and x, respectively.

  • density (float 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).

  • linewidth (float 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.

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

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

  • arrowsize (float) – Scaling factor for the arrow size.

  • arrowstyle (str) – Arrow style specification. See ~matplotlib.patches.FancyArrowPatch.

  • minlength (float) – Minimum length of streamline in axes coordinates.

  • start_points (Nx2 array) – Coordinates of starting points for the streamlines in data coordinates (the same coordinates as the x and y arrays).

  • zorder (float) – The zorder of the streamlines and arrows. Artists with lower zorder values are drawn first.

  • maxlength (float) – Maximum length of streamline in axes coordinates.

  • integration_direction ({'forward', 'backward', 'both'}, default: 'both') – Integrate the streamline in forward, backward or both directions.

  • data (indexable object, optional) – DATA_PARAMETER_PLACEHOLDER

  • broken_streamlines (boolean, 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.

Returns:

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.

Return type:

StreamplotSet