.. _pylab_examples-barb_demo: pylab_examples example code: barb_demo.py ========================================= .. plot:: /home/tcaswell/source/p/matplotlib/doc/mpl_examples/pylab_examples/barb_demo.py :: ''' Demonstration of wind barb plots ''' import matplotlib.pyplot as plt import numpy as np x = np.linspace(-5, 5, 5) X, Y = np.meshgrid(x, x) U, V = 12*X, 12*Y data = [(-1.5, .5, -6, -6), (1, -1, -46, 46), (-3, -1, 11, -11), (1, 1.5, 80, 80), (0.5, 0.25, 25, 15), (-1.5, -0.5, -5, 40)] data = np.array(data, dtype=[('x', np.float32), ('y', np.float32), ('u', np.float32), ('v', np.float32)]) # Default parameters, uniform grid ax = plt.subplot(2, 2, 1) ax.barbs(X, Y, U, V) # Arbitrary set of vectors, make them longer and change the pivot point #(point around which they're rotated) to be the middle ax = plt.subplot(2, 2, 2) ax.barbs(data['x'], data['y'], data['u'], data['v'], length=8, pivot='middle') # Showing colormapping with uniform grid. Fill the circle for an empty barb, # don't round the values, and change some of the size parameters ax = plt.subplot(2, 2, 3) ax.barbs(X, Y, U, V, np.sqrt(U*U + V*V), fill_empty=True, rounding=False, sizes=dict(emptybarb=0.25, spacing=0.2, height=0.3)) # Change colors as well as the increments for parts of the barbs ax = plt.subplot(2, 2, 4) ax.barbs(data['x'], data['y'], data['u'], data['v'], flagcolor='r', barbcolor=['b', 'g'], barb_increments=dict(half=10, full=20, flag=100), flip_barb=True) # Masked arrays are also supported masked_u = np.ma.masked_array(data['u']) masked_u[4] = 1000 # Bad value that should not be plotted when masked masked_u[4] = np.ma.masked # Identical plot to panel 2 in the first figure, but with the point at #(0.5, 0.25) missing (masked) fig2 = plt.figure() ax = fig2.add_subplot(1, 1, 1) ax.barbs(data['x'], data['y'], masked_u, data['v'], length=8, pivot='middle') plt.show() Keywords: python, matplotlib, pylab, example, codex (see :ref:`how-to-search-examples`)