pyqtgraph的等级曲线：isocurve

Question

有没有人知道使用isocurve从pyqtgraph获得这个（level curves from matplotlib）的方法？ 这里是我的代码...

谢谢！

from pyqtgraph.Qt import QtGui,QtCore 
import numpy as np 
import pyqtgraph as pg 
import sys 

#data creation 
app=QtGui.QApplication([]) 
x = np.linspace(0,6.28,30) 
y = x[:] 
xx,yy = np.meshgrid(x,y) 
z = np.sin(xx)+np.cos(yy) 

win = pg.GraphicsWindow() 
win.setWindowTitle('esempio isocurve') 
vb = win.addViewBox() 
img = pg.ImageItem(z) 
vb.addItem(img) #visualizes img in viewbox vb 
vb.setAspectLocked() #set img proportions (?) 

c = pg.IsocurveItem(data=z,level=2,pen='r') 
c.setParentItem(img) #set img as parent of the isocurve item c (?) 
c.setZValue(10) #I DO NOT KNOW THE MEANING OF THIS, JUST COPIED FROM THE EXAMPLE isocurve.py 

vb.addItem(c) 

win.show() 
sys.exit(app.exec_()) 

Answer 1

[解决]我不得不为了编辑“functions.py”在行〜1500摆脱错误的

"TypeError: Cannot cast ufunc add output from dtype('int32') to dtype('uint8') with casting rule 'same_kind'". 

文件“functions.py”位于 C：\ Users \ my_name \ AppData \ Local \ Programs \ Python \ Python35 \ Lib \ site-packages \ pyqtgraph（Windows搜索引擎没有找到它，因为它位于隐藏文件夹内！）。下面是修改通过this Google Group建议：

index += (fields[i,j] * 2**vertIndex) 

成为

index += (fields[i,j] * 2**vertIndex).astype(np.ubyte). 

在我的代码，我必须设置

level=0 

，而不是

level=2 

，为2大于马z的最大值。换句话说，我试图画一条1500米山峰的2000米水平曲线。永远记得提供一个合适的水平！ Here's the correct output（-.-'）