如何将 matplotlib 图的输出作为 SVG 获取? [英] How can I get the output of a matplotlib plot as an SVG?
问题描述
我需要获取 matplotlib 绘图的输出并将其转换为可以在激光切割机上使用的 SVG 路径.
I need to take the output of a matplotlib plot and turn it into an SVG path that I can use on a laser cutter.
import matplotlib.pyplot as plt
import numpy as np
x = np.arange(0,100,0.00001)
y = x*np.sin(2*pi*x)
plt.plot(y)
plt.show()
例如，您会在下方看到一个波形.我希望能够将此波形输出或保存为 SVG 路径，以便我以后可以在 Adobe Illustrator 等程序中使用.
For example, below you see a waveform. I would like to be able to output or save this waveform as an SVG path that I can later work with in a program such as Adobe Illustrator.
我知道 matplotlib 可以使用一个名为Cairo"的 SVG 库(matplotlib.use('Cairo'))，但是我不清楚这是否能让我访问我需要的 SVG 路径，即使 matplotlib 现在将使用 Cairo 生成绘图.
I am aware of an SVG library called "Cairo" that matplotlib can use (matplotlib.use('Cairo')), however it's not clear to me that this will give me access to the SVG path that I need, even though matplotlib will now be using Cairo to generate the plot.
我的系统上确实有 cairo，并且可以成功绘制一个由 SVG 路径组成的示例，我确实可以在 Illustrator 中对其进行编辑，但我无法将上面的等式转换为 SVG 路径.
I do have cairo working on my system, and can successfully draw an example composed of SVG paths that I can indeed edit in Illustrator, but I don't have a way to take my equation above into an SVG path.
import cairo
from cairo import SVGSurface, Context, Matrix
s = SVGSurface('example1.svg', WIDTH, HEIGHT)
c = Context(s)
# Transform to normal cartesian coordinate system
m = Matrix(yy=-1, y0=HEIGHT)
c.transform(m)
# Set a background color
c.save()
c.set_source_rgb(0.3, 0.3, 1.0)
c.paint()
c.restore()
# Draw some lines
c.move_to(0, 0)
c.line_to(2 * 72, 2* 72)
c.line_to(3 * 72, 1 * 72)
c.line_to(4 * 72, 2 * 72)
c.line_to(6 * 72, 0)
c.close_path()
c.save()
c.set_line_width(6.0)
c.stroke_preserve()
c.set_source_rgb(0.3, 0.3, 0.3)
c.fill()
c.restore()
# Draw a circle
c.save()
c.set_line_width(6.0)
c.arc(1 * 72, 3 * 72, 0.5 * 72, 0, 2 * pi)
c.stroke_preserve()
c.set_source_rgb(1.0, 1.0, 0)
c.fill()
c.restore()
# Save as a SVG and PNG
s.write_to_png('example1.png')
s.finish()
(注意这里显示的图片是png，因为stackoverflow不接受svg图形显示)
(note that the image displayed here is a png, as stackoverflow doesn't accept svg graphics for display)
推荐答案
您很可能希望修复图像大小并摆脱各种背景和轴标记:
You will most probably want to fix the image size and get rid of all sorts of backgrounds and axis markers:
import matplotlib.pyplot as plt
import numpy as np
plt.figure(figsize=[6, 6])
x = np.arange(0, 100, 0.00001)
y = x*np.sin(2* np.pi * x)
plt.plot(y)
plt.axis('off')
plt.gca().set_position([0, 0, 1, 1])
plt.savefig("test.svg")
生成的 SVG 文件只包含一个额外的元素，因为 savefig 确实想保存图形背景.这个背景的颜色很容易改成'none'，但它似乎并没有摆脱它.无论如何，SVG 非常干净，而且比例正确(每单位 1/72").
The resulting SVG file contains only one extra element, as savefig really wants to save the figure background. The color of this background is easy to change to 'none', but it does not seem to get rid of it. Anyway, the SVG is very clean otherwise and in the correct scale (1/72" per unit).
这篇关于如何将 matplotlib 图的输出作为 SVG 获取?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
