New Matplotlib using Image Element demo - shows a Spectrogram

DemoPrograms/Demo_Matplotlib_Image_Elem.py

@@ -0,0 +1,133 @@
+import PySimpleGUI as sg
+import numpy as np
+from matplotlib.backends.backend_tkagg import FigureCanvasAgg
+import matplotlib.pyplot as plt
+import io
+
+"""
+    Demo_Matplotlib_Image_Elem Demo
+    
+    Demo to show
+        * How to use an Image element to show a Matplotlib figure
+        * How to draw a Spectrogram
+        * Hide the Image when a figure isn't present (shrinks the window automatically)
+        
+    The example graph can be found in the matplotlib gallery:
+    https://matplotlib.org/stable/gallery/images_contours_and_fields/specgram_demo.html        
+    
+    Copyright 2021 PySimpleGUI
+"""
+
+
+# .d88888b    dP                       dP
+# 88.    "'   88                       88
+# `Y88888b. d8888P .d8888b. 88d888b. d8888P
+#       `8b   88   88'  `88 88'  `88   88
+# d8'   .8P   88   88.  .88 88         88
+#  Y88888P    dP   `88888P8 dP         dP
+# oooooooooooooooooooooooooooooooooooooooooo of your Matplotlib code
+
+
+def your_matplotlib_code():
+    # Fixing random state for reproducibility
+    np.random.seed(19680801)
+
+    dt = 0.0005
+    t = np.arange(0.0, 20.0, dt)
+    s1 = np.sin(2 * np.pi * 100 * t)
+    s2 = 2 * np.sin(2 * np.pi * 400 * t)
+
+    # create a transient "chirp"
+    s2[t <= 10] = s2[12 <= t] = 0
+
+    # add some noise into the mix
+    nse = 0.01 * np.random.random(size=len(t))
+
+    x = s1 + s2 + nse  # the signal
+    NFFT = 1024  # the length of the windowing segments
+    Fs = int(1.0 / dt)  # the sampling frequency
+
+    fig, (ax1, ax2) = plt.subplots(nrows=2)
+    ax1.plot(t, x)
+    Pxx, freqs, bins, im = ax2.specgram(x, NFFT=NFFT, Fs=Fs, noverlap=900)
+
+    return fig
+
+
+#  88888888b                dP
+#  88                       88
+#  88aaaa    88d888b. .d888b88
+#  88        88'  `88 88'  `88
+#  88        88    88 88.  .88
+#  88888888P dP    dP `88888P8
+# ooooooooooooooooooooooooooooo of your Matplotlib code
+
+
+
+
+# dP     dP           dP
+# 88     88           88
+# 88aaaaa88a .d8888b. 88  88d888b. .d8888b. 88d888b.
+# 88     88  88ooood8 88  88'  `88 88ooood8 88'  `88
+# 88     88  88.  ... 88  88.  .88 88.  ... 88
+# dP     dP  `88888P' dP  88Y888P' `88888P' dP
+# ooooooooooooooooooooooo~88~oooooooooooooooooooooooo function
+#                         dP
+
+def draw_figure(element, figure):
+    """
+    Draws the previously created "figure" in the supplied Image Element
+
+    :param element: an Image Element
+    :param figure: a Matplotlib figure
+    :return: The figure canvas
+    """
+
+    plt.close('all')  # erases previously drawn plots
+    canv = FigureCanvasAgg(figure)
+    buf = io.BytesIO()
+    canv.print_figure(buf, format='png')
+    if buf is None:
+        return None
+    buf.seek(0)
+    element.update(data=buf.read(), visible=True)
+    return canv
+
+
+
+#  .88888.  dP     dP dP
+# d8'   `88 88     88 88
+# 88        88     88 88
+# 88   YP88 88     88 88
+# Y8.   .88 Y8.   .8P 88
+#  `88888'  `Y88888P' dP
+# ooooooooooooooooooooooo
+
+
+def main():
+    # define the window layout
+    layout = [[sg.Text('Spectrogram test')],
+              [sg.pin(sg.Image(key='-IMAGE-'))],
+              [sg.Button('Ok'), sg.B('Clear')]]
+
+    # create the form and show it without the plot
+    window = sg.Window('Spectrogram', layout, element_justification='c', font='Helvetica 14')
+
+    while True:
+        # add the plot to the window
+        event, values = window.read()
+        if event == sg.WIN_CLOSED:
+            break
+        elif event == 'Ok':
+            draw_figure(window['-IMAGE-'], your_matplotlib_code())
+        elif event == 'Clear':
+            plt.close('all')                                # close all plots
+            window['-IMAGE-'].update()                      # clears the image
+            window['-IMAGE-'].update(visible=False)         # hides the blank image
+
+
+    window.close()
+
+
+if __name__ == '__main__':
+    main()