Bokeh : Plot a spectrogram

I am new to Bookeh and I have a task to plot the spectrogram in bokeh.

I am using to get the spectrogram. In the above example they are using pcolormesh() of matplotlib to plot the spectrogram. How can I get the same(or equivalent) spectrogram plot in bokeh.

I have tried to get it done by plotting a heatmap by using the folowing code:

    f, t, Sxx = spectrogram(raw_data, fs)
    for freq in range(f.shape[0]):
        for time in range(t.shape[0]):
            df_spectogram.loc[i] = [f[freq],t[time],Sxx[freq][time]]
            i = i+1

    TOOLS = "hover,save,pan,box_zoom,reset,wheel_zoom"
    PALETTE = ['#081d58', '#253494', '#225ea8', '#1d91c0', '#41b6c4', '#7fcdbb', '#c7e9b4', '#edf8b1', '#ffffd9']
    mapper = LinearColorMapper(palette=PALETTE, low=numpy.min(Sxx), high=numpy.max(Sxx))
    spectogram_figure = figure(title="Spectogram",x_axis_location="below", plot_width=900, plot_height=400,
    spectogram_figure.background_fill_color = "#eaeaea"
    spectrogram_source = ColumnDataSource(data=dict(Sxx=df_spectogram['Sxx'],Frequency=df_spectogram['Frequency'],Time=df_spectogram['Time']))"Time", y="Frequency", source=spectrogram_source, fill_color={'field': 'Sxx', 'transform': mapper}, line_color=None)