PYTHON

pyqt5 display math

import sys
import matplotlib as mpl
from matplotlib.backends.backend_agg import FigureCanvasAgg
from PySide import QtGui, QtCore

def mathTex_to_QPixmap(mathTex, fs):

    #---- set up a mpl figure instance ----

    fig = mpl.figure.Figure()
    fig.patch.set_facecolor('none')
    fig.set_canvas(FigureCanvasAgg(fig))
    renderer = fig.canvas.get_renderer()

    #---- plot the mathTex expression ----

    ax = fig.add_axes([0, 0, 1, 1])
    ax.axis('off')
    ax.patch.set_facecolor('none')
    t = ax.text(0, 0, mathTex, ha='left', va='bottom', fontsize=fs)

    #---- fit figure size to text artist ----

    fwidth, fheight = fig.get_size_inches()
    fig_bbox = fig.get_window_extent(renderer)

    text_bbox = t.get_window_extent(renderer)

    tight_fwidth = text_bbox.width * fwidth / fig_bbox.width
    tight_fheight = text_bbox.height * fheight / fig_bbox.height

    fig.set_size_inches(tight_fwidth, tight_fheight)

    #---- convert mpl figure to QPixmap ----

    buf, size = fig.canvas.print_to_buffer()
    qimage = QtGui.QImage.rgbSwapped(QtGui.QImage(buf, size[0], size[1],
                                                  QtGui.QImage.Format_ARGB32))
    qpixmap = QtGui.QPixmap(qimage)

    return qpixmap

pyqt math

import sys
import time

import numpy as np

from matplotlib.backends.qt_compat import QtWidgets
from matplotlib.backends.backend_qtagg import (
    FigureCanvas, NavigationToolbar2QT as NavigationToolbar)
from matplotlib.figure import Figure


class ApplicationWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        self._main = QtWidgets.QWidget()
        self.setCentralWidget(self._main)
        layout = QtWidgets.QVBoxLayout(self._main)

        static_canvas = FigureCanvas(Figure(figsize=(5, 3)))
        # Ideally one would use self.addToolBar here, but it is slightly
        # incompatible between PyQt6 and other bindings, so we just add the
        # toolbar as a plain widget instead.
        layout.addWidget(NavigationToolbar(static_canvas, self))
        layout.addWidget(static_canvas)

        dynamic_canvas = FigureCanvas(Figure(figsize=(5, 3)))
        layout.addWidget(dynamic_canvas)
        layout.addWidget(NavigationToolbar(dynamic_canvas, self))

        self._static_ax = static_canvas.figure.subplots()
        t = np.linspace(0, 10, 501)
        self._static_ax.plot(t, np.tan(t), ".")

        self._dynamic_ax = dynamic_canvas.figure.subplots()
        t = np.linspace(0, 10, 101)
        # Set up a Line2D.
        self._line, = self._dynamic_ax.plot(t, np.sin(t + time.time()))
        self._timer = dynamic_canvas.new_timer(50)
        self._timer.add_callback(self._update_canvas)
        self._timer.start()

    def _update_canvas(self):
        t = np.linspace(0, 10, 101)
        # Shift the sinusoid as a function of time.
        self._line.set_data(t, np.sin(t + time.time()))
        self._line.figure.canvas.draw()


if __name__ == "__main__":
    # Check whether there is already a running QApplication (e.g., if running
    # from an IDE).
    qapp = QtWidgets.QApplication.instance()
    if not qapp:
        qapp = QtWidgets.QApplication(sys.argv)

    app = ApplicationWindow()
    app.show()
    app.activateWindow()
    app.raise_()
    qapp.exec()