在matplotlib中获取带有hexbin的bin坐标

Question

我使用matplotlib的方法hexbin计算我的数据的2d直方图.但我想得到六边形中心的坐标,以便进一步处理结果.

我get_array()在结果上使用方法获得了值,但我无法弄清楚如何获取bin坐标.

我尝试计算它们给定的箱数和我的数据范围,但我不知道每个方向的箱的确切数量. gridsize=(10,2)应该做的伎俩但它似乎不起作用.

任何的想法？

Answer 1

我觉得这很有效.

from __future__ import division
import numpy as np
import math
import matplotlib.pyplot as plt

def generate_data(n):
    """Make random, correlated x & y arrays"""
    points = np.random.multivariate_normal(mean=(0,0),
        cov=[[0.4,9],[9,10]],size=int(n))
    return points

if __name__ =='__main__':

    color_map = plt.cm.Spectral_r
    n = 1e4
    points = generate_data(n)

    xbnds = np.array([-20.0,20.0])
    ybnds = np.array([-20.0,20.0])
    extent = [xbnds[0],xbnds[1],ybnds[0],ybnds[1]]

    fig=plt.figure(figsize=(10,9))
    ax = fig.add_subplot(111)
    x, y = points.T
    # Set gridsize just to make them visually large
    image = plt.hexbin(x,y,cmap=color_map,gridsize=20,extent=extent,mincnt=1,bins='log')
    # Note that mincnt=1 adds 1 to each count
    counts = image.get_array()
    ncnts = np.count_nonzero(np.power(10,counts))
    verts = image.get_offsets()
    for offc in xrange(verts.shape[0]):
        binx,biny = verts[offc][0],verts[offc][1]
        if counts[offc]:
            plt.plot(binx,biny,'k.',zorder=100)
    ax.set_xlim(xbnds)
    ax.set_ylim(ybnds)
    plt.grid(True)
    cb = plt.colorbar(image,spacing='uniform',extend='max')
    plt.show()