pyqtgraph 散点图项目设置画笔

Question

我正在尝试通过 setBrush 传递列表参数。

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

app = QtGui.QApplication([])
mw = QtGui.QMainWindow()
mw.resize(800,800)
view = pg.GraphicsLayoutWidget()  
mw.setCentralWidget(view)
mw.setWindowTitle('pyqtgraph example: ScatterPlot')
w1 = view.addPlot()
x = [1,2,3,4,5,6,7,8,9,10]
y = [10,8,6,4,2,20,18,16,14,12]
s1 = pg.ScatterPlotItem(x,y,size=10, pen=pg.mkPen(None), brush=pg.mkBrush(255, 255, 255, 120))
s1.setBrush(['r']*10, mask=None)
w1.addItem(s1)
mw.show()

当我运行这段代码时，出现如下错误：

Traceback (most recent call last): File "", line 1, in

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 467, in setBrush self.updateSpots(dataSet)

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 553, in updateSpots self.fragmentAtlas.getAtlas() # generate atlas so source widths are available.

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 193, in getAtlas self.buildAtlas()

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 143, in buildAtlas img = renderSymbol(key[0], key[1], sourceRect.pen, sourceRect.brush)

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 74, in renderSymbol drawSymbol(p, symbol, size, pen, brush)

File "C:\Python34\lib\site-packages\pyqtgraph\graphicsItems\ScatterPlotItem.py", line 49, in drawSymbol painter.setBrush(brush) TypeError: arguments did not match any overloaded call: QPainter.setBrush(QBrush): argument 1 has unexpected type 'str' QPainter.setBrush(Qt.BrushStyle): argument 1 has unexpected type 'str'

如何通过 setBrush 传递列表？我必须为不同的点分配不同的颜色。

Answer 1

添加s.setBrush(QtGui.QBrush({your parameters})) 例如：

QtGui.QBrush()
QtGui.QBrush(Qt.BrushStyle bs)
QtGui.QBrush(QColor颜色,Qt.BrushStyle风格=Qt.SolidPattern)
QtGui.QBrush(Qt.GlobalColor颜色,Qt.BrushStyle风格=Qt.SolidPattern)
QtGui.QBrush(QColor颜色,QPixmap像素图)
QtGui.QBrush(Qt.GlobalColor颜色,QPixmap像素图)
QtGui.QBrush(QPixmap 像素图)
QtGui.QBrush(QImage图片)
QtGui.QBrush(QGradient渐变)
QtGui.QBrush(QBrush刷)
QtGui.QBrush（QVariant 变体）

在您的代码中：

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

app = QtGui.QApplication(sys.argv)
mw = QtGui.QMainWindow()
mw.resize(800, 800)
view = pg.GraphicsLayoutWidget()
mw.setCentralWidget(view)
mw.setWindowTitle('pyqtgraph example: ScatterPlot')
w1 = view.addPlot()
x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
y = [10, 8, 6, 4, 2, 20, 18, 16, 14, 12]

# Create seed for the random
time = QtCore.QTime.currentTime()
QtCore.qsrand(time.msec())

for i in range(len(x)):
    s = pg.ScatterPlotItem([x[i]], [y[i]], size=10, pen=pg.mkPen(None))  # brush=pg.mkBrush(255, 255, 255, 120))
    s.setBrush(QtGui.QBrush(QtGui.QColor(QtCore.qrand() % 256, QtCore.qrand() % 256, QtCore.qrand() % 256)))
    w1.addItem(s)
mw.show()
sys.exit(QtGui.QApplication.exec_())

输出：

如果要为前 5 个点 (x: 1-5) 设置红色，为另外 5 个点 (x: 6-10) 设置蓝色

import sys
from pyqtgraph.Qt import QtGui
import pyqtgraph as pg

app = QtGui.QApplication(sys.argv)
mw = QtGui.QMainWindow()
mw.resize(800, 800)
view = pg.GraphicsLayoutWidget()
mw.setCentralWidget(view)
mw.setWindowTitle('pyqtgraph example: ScatterPlot')
w1 = view.addPlot()
x = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
y = [10, 8, 6, 4, 2, 20, 18, 16, 14, 12]

color = QtGui.QColor("#0000FF")
s = pg.ScatterPlotItem(x[:5], y[:5], size=10, pen=pg.mkPen(None), brush='r')
w1.addItem(s)
s = pg.ScatterPlotItem(x[5:], y[5:], size=10, pen=pg.mkPen(None), brush='b')
w1.addItem(s)
mw.show()
sys.exit(QtGui.QApplication.exec_())

Answer 2

如果要更改圆点的颜色，可以将列表传递给 symbolBrush 关键字。您的代码将变为：

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

app = QtGui.QApplication([])
mw = QtGui.QMainWindow()
mw.resize(800,800)
view = pg.GraphicsLayoutWidget()
mw.setCentralWidget(view)
mw.setWindowTitle('pyqtgraph example: ScatterPlot')
w1 = view.addPlot()
x = [1,2,3,4,5,6,7,8,9,10]
y = [10,8,6,4,2,20,18,16,14,12]

brush_list = [pg.mkColor(c) for c in "rgbcmykwrg"]

p1 = w1.plot()
s1 = p1.setData(x=x, y=y, size=10, pen=pg.mkPen(None), brush='g', symbol='o', symbolBrush=brush_list, symbolPen='r')
mw.show()
sys.exit(QtGui.QApplication.exec_())

我需要做 p1 = w1.plot() 才能让它工作，但我对所有 pyqtgraph 对象都不够流利，无法告诉你它的作用。

我必须将颜色字符串（或元组或其他）转换为 pg.mkColor() 对象才能正常工作（尽管文档说不需要）

请注意，brush 关键字会填充图表，直到您指定某个值（例如 x 轴），这对线很有用，但对点不显示任何内容，如您所见在图像中。

symbolPen关键字可用于点的线条颜色。

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