Programming: Moving away from pyplot

Matplotlib has two interfaces: pyplot (based on MATLAB) or object-oriented (OO) interface. Pyplot inteface is causing problems with backend on some headless stations. The purpose of this wiki is to explain how to refactor the code to a all OO interface. With this, figures are not displayed to the frontend, but saved. In this case, we utilize an instance of axes.Axes in order to render visualizations on an instance of figure.Figure.

OO Approach:

from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
from matplotlib.figure import Figure

fig = Figure()
FigureCanvas(fig)
ax = fig.add_subplot(111)
ax.plot([1, 2, 3])
ax.set_title('hi mom')
ax.grid(True)
ax.set_xlabel('time')
ax.set_ylabel('volts')
fig.savefig('test.png')

test:
        from matplotlib.backends.backend_agg import FigureCanvasAgg as FigureCanvas
        from matplotlib.figure import Figure
        fig_disc = Figure()
        FigureCanvas(fig_disc)
        ax_disc = fig_disc.add_axes((0, 0, 1, 1))
        # get percentile for automatic contrast adjustment
        data_display = np.mean(data[xc - param.size_RL:xc + param.size_RL, :, :], axis=0).transpose()
        percmin = np.percentile(data_display, 10)
        percmax = np.percentile(data_display, 90)
        # display image
        ax_disc.matshow(data_display, cmap='gray', clim=[percmin, percmax], origin='lower')
        ax_disc.set_title('Anatomical image')
        # ax.autoscale(enable=False)  # to prevent autoscale of axis when displaying plot
        ax_disc.scatter(yc + param.shift_AP_visu, init_disc[0], c='yellow', s=50)
        ax_disc.text(yc + param.shift_AP_visu + 4, init_disc[0], str(init_disc[1]) + '/' + str(init_disc[1] + 1),
                     verticalalignment='center', horizontalalignment='left', color='pink', fontsize=15)
        fig_disc.savefig('fig_save_init_disc.png')

More info:

• https://matplotlib.org/tutorials/introductory/lifecycle.html