def insertIndent():
            if self.useTabs:
                cursor.insertText('\t')
            else:  # indent to integer count of indents from line start
                charsToInsert = self.width - (len(self._qpart.textBeforeCursor()) % self.width)
                cursor.insertText(' ' * charsToInsert)
def voltage(title, pos, voltage, ax=0):
    """plot voltage vs. position"""
    if ax == 0:
        ax = plt.gca()
    ax.set_title('{} / V'.format(title))
    ax.grid(True)
    ax.plot(pos, voltage)