我有以下代码:
from mpl_toolkits.axes_grid.axislines import SubplotZero
from matplotlib.transforms import BlendedGenericTransform
import matplotlib.pyplot as plt
import numpy
if 1:
fig = plt.figure(1)
ax = SubplotZero(fig, 111)
fig.add_subplot(ax)
ax.axhline(linewidth=1.7, color="black")
ax.axvline(linewidth=1.7, color="black")
plt.xticks([1])
plt.yticks([])
ax.text(0, 1.05, 'y', transform=BlendedGenericTransform(ax.transData, ax.transAxes), ha='center')
ax.text(1.05, 0, 'x', transform=BlendedGenericTransform(ax.transAxes, ax.transData), va='center')
for direction in ["xzero", "yzero"]:
ax.axis[direction].set_axisline_style("-|>")
ax.axis[direction].set_visible(True)
for direction in ["left", "right", "bottom", "top"]:
ax.axis[direction].set_visible(False)
x = numpy.linspace(-0.5, 1., 1000)
ax.plot(x, numpy.sin(x*numpy.pi), linewidth=1.2, color="black")
plt.show()
生成以下图像:
与实际图表相比,轴箭头看起来有些残留。我如何将它们的尺寸放大一点,以便它们在轴的宽度方面看起来正常。
此外 - 这里很难看清,但箭头的内部是蓝色的 - 如何将其更改为黑色?
最佳答案
我的解决方案与 nebffa 的解决方案基本相同。我创建了一个最小示例,用于计算 y 轴的箭头宽度和长度以匹配为 x 轴指定的箭头宽度和长度。我希望这可能对其他人有所帮助。
import pylab as pl
fig = pl.figure()
ax = fig.add_subplot(111)
x = pl.arange(-5,5,0.1)
ax.plot(x, x**2-8.8)
xmin, xmax = ax.get_xlim()
ymin, ymax = ax.get_ylim()
# removing the default axis on all sides:
for side in ['bottom','right','top','left']:
ax.spines[side].set_visible(False)
# removing the axis ticks
pl.xticks([]) # labels
pl.yticks([])
ax.xaxis.set_ticks_position('none') # tick markers
ax.yaxis.set_ticks_position('none')
# wider figure for demonstration
fig.set_size_inches(4,2.2)
# get width and height of axes object to compute
# matching arrowhead length and width
dps = fig.dpi_scale_trans.inverted()
bbox = ax.get_window_extent().transformed(dps)
width, height = bbox.width, bbox.height
# manual arrowhead width and length
hw = 1./20.*(ymax-ymin)
hl = 1./20.*(xmax-xmin)
lw = 1. # axis line width
ohg = 0.3 # arrow overhang
# compute matching arrowhead length and width
yhw = hw/(ymax-ymin)*(xmax-xmin)* height/width
yhl = hl/(xmax-xmin)*(ymax-ymin)* width/height
# draw x and y axis
ax.arrow(xmin, 0, xmax-xmin, 0., fc='k', ec='k', lw = lw,
head_width=hw, head_length=hl, overhang = ohg,
length_includes_head= True, clip_on = False)
ax.arrow(0, ymin, 0., ymax-ymin, fc='k', ec='k', lw = lw,
head_width=yhw, head_length=yhl, overhang = ohg,
length_includes_head= True, clip_on = False)
# clip_on = False if only positive x or y values.
pl.savefig('arrow_axis.png', dpi = 300)
产生:
关于python - 如何用matplotlib制作 'fuller'轴箭头,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17646247/