Log curve plot demoΒΆ

../_images/logcurve.png 

import numpy as np

np.seterr(all="raise")

from qtpy.QtCore import Qt

from qwt import QwtLogScaleEngine, QwtPlot, QwtPlotCurve
from qwt.tests import utils


class LogCurvePlot(QwtPlot):
    def __init__(self):
        super(LogCurvePlot, self).__init__(
            "LogCurveDemo.py (or how to handle -inf values)"
        )
        self.enableAxis(QwtPlot.xBottom)
        self.setAxisScaleEngine(QwtPlot.yLeft, QwtLogScaleEngine())
        x = np.arange(0.0, 10.0, 0.1)
        y = 10 * np.cos(x) ** 2 - 0.1
        QwtPlotCurve.make(x, y, linecolor=Qt.magenta, plot=self, antialiased=True)
        self.replot()


def test_logcurve():
    """Log curve demo"""
    utils.test_widget(LogCurvePlot, size=(800, 500))


if __name__ == "__main__":
    test_logcurve()