scatter

问题 How could I add trendline to a dot graph drawn using matplotlib.scatter? 回答1: as explained here With help from numpy one can calculate for example a linear fitting. # plot the data itself pylab.plot(x,y,'o') # calc the trendline z = numpy.polyfit(x, y, 1) p = numpy.poly1d(z) pylab.plot(x,p(x),"r--") # the line equation: print "y=%.6fx+(%.6f)"%(z[0],z[1]) 来源： https://stackoverflow.com/questions/26447191/how-to-add-trendline-in-python-matplotlib-dot-scatter-graphs

问题 I would like to scale the markersize of matplotlib.pyplot.Axes.scatter plot based on the number of points on the x/y-axis. import matplotlib.pyplot as plt import numpy as np vmin = 1 vmax = 11 x = np.random.randint(vmin, vmax, 5) y = np.random.randint(vmin, vmax, 5) fig, ax = plt.subplots() for v in np.arange(vmin, vmax): ax.axvline(v - 0.5) ax.axvline(v + 0.5) ax.axhline(v - 0.5) ax.axhline(v + 0.5) ax.set_xlim(vmin - 0.5, vmax + 0.5) ax.set_ylim(vmin - 0.5, vmax + 0.5) ax.scatter(x, y) ax

问题 I would like to know how to make matplotlib\'s scatter function colour points by a third variable. Questions gnuplot linecolor variable in matplotlib? and Matplotlib scatterplot; colour as a function of a third variable posed similar queries, however, the answers to those questions don\'t address my issue: the use of c=arraywhichspecifiespointcolour in the scatter function only sets the fill colour, not the edge colour. This means that the use of c=arr... fails when using markersymbol=\'+\' ,

问题 I want to partition matrix into blocks (not stripes) and then distribute this blocks using MPI_Scatter. I came up with solution which works, but I think it is far from \"best practice\". I have 8x8 matrix, filled with numbers from 0 to 63. Then I divide it into 4 4x4 blocks, using MPI_Type_vector and distribute it via MPI_Send, but this require some extra computation since i have to compute offsets for each block in big matrix. If I use scatter, first (top left) block is transfered OK, but