# -*- coding: utf-8 -*- """ This example shows how to insert text into a scene using TextItem. This class is for displaying text that is anchored to a particular location in the data coordinate system, but which is always displayed unscaled. For text that scales with the data, use QTextItem. For text that can be placed in a layout, use LabelItem. """ import initExample ## Add path to library (just for examples; you do not need this) import pyqtgraph as pg from pyqtgraph.Qt import QtCore, QtGui import numpy as np x = np.linspace(-20, 20, 1000) y = np.sin(x) / x plot = pg.plot() ## create an empty plot widget plot.setYRange(-1, 2) plot.setWindowTitle('pyqtgraph example: text') curve = plot.plot(x,y) ## add a single curve ## Create text object, use HTML tags to specify color/size text = pg.TextItem(html='
This is the
PEAK
', anchor=(-0.3,1.3), border='w', fill=(0, 0, 255, 100)) plot.addItem(text) text.setPos(0, y.max()) ## Draw an arrowhead next to the text box arrow = pg.ArrowItem(pos=(0, y.max()), angle=-45) plot.addItem(arrow) ## Set up an animated arrow and text that track the curve curvePoint = pg.CurvePoint(curve) plot.addItem(curvePoint) text2 = pg.TextItem("test", anchor=(0.5, -1.0)) text2.setParentItem(curvePoint) arrow2 = pg.ArrowItem(angle=90) arrow2.setParentItem(curvePoint) ## update position every 10ms index = 0 def update(): global curvePoint, index index = (index + 1) % len(x) curvePoint.setPos(float(index)/(len(x)-1)) #text2.viewRangeChanged() text2.setText('[%0.1f, %0.1f]' % (x[index], y[index])) timer = QtCore.QTimer() timer.timeout.connect(update) timer.start(10) ## Start Qt event loop unless running in interactive mode or using pyside. if __name__ == '__main__': import sys if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'): QtGui.QApplication.instance().exec_()