Question

我正在尝试使用matplotlib绘制并旋转围绕Julia中特定点的矩形进行绘图。但是，似乎我必须结合两个转换来完成这项工作，我不知道该怎么做。

using PyPlot
using PyCall
@pyimport matplotlib.patches as patches
@pyimport matplotlib as mpl

fig = figure(1)
ax = gca()
axis([-4,4,-4,4])

# specify non-rotated rectangle
length = 4
width = 2
rect = patches.Rectangle([1,1],length,width,color="blue",alpha=0.3)
rect_rotated = patches.Rectangle([1,1],length,width,color="red",alpha=0.3)
 # rotate about the following point
point = [3,2]

# try to rotate rectangle using matplotlib's transformations
t1 = mpl.transforms[:Affine2D]()
t1[:rotate_deg_around](point[1],point[2], -30)

# apparently one also has to transform between data coordinate system and display coordinate system
t2 = ax[:transData]

我现在要做的是为了结合转换：

t3 = t1 + t2
rect_rotated[:set_transform](t3)
ax[:add_patch](rect)
ax[:add_patch](rect_rotated)

但是，我收到以下错误

错误：LoadError：MethodError：没有匹配的方法+（:: PyCall.PyObject，:: PyCall.PyObject）

我认为是因为PyPlot-Wrapper不支持“+” - 符号来组合底层转换。

有谁知道如何使这项工作？谢谢

Answer 1

Python使用第一个对象的方法实现运算符重载，例如t3 = t1 + t2相当于t3 = t1.__add__(t2)。

在朱莉娅，这变成了 t3 = t1[:__add__](t2)

Answer 2

有了@ DavidP.Sanders的评论，工作代码如下所示：

using PyPlot
using PyCall
@pyimport matplotlib.patches as patches
@pyimport matplotlib as mpl

fig = figure(1)
ax =gca()


# specify non-rotated rectangle
length = 4
width = 2
rect = patches.Rectangle([1,1],length,width,color="blue",alpha=0.3)
rect_rotated = patches.Rectangle([1,1],length,width,color="red",alpha=0.3)
 # rotate about the following point
point = [3,2]

# try to rotate rectangle using matplotlib's transformations
t1 = mpl.transforms[:Affine2D]()
t1[:rotate_deg_around](point[1],point[2], -30)

# apparently one also has to transform between data coordinate system and display coordinate system
t2 = ax[:transData]
t3 = t1[:__add__](t2)
rect_rotated[:set_transform](t3)
ax[:add_patch](rect)
ax[:add_patch](rect_rotated)
axis([-1,6,-1,6],"equal")

<强>结果： Rotated rectangle

使用Julia中的PyPlot旋转关于特定点的矩形

2 个答案: