'Select or deselect one sensor.'

def select_one(self, ind):

    ch_name = self.ch_names[ind]
    if (ch_name in self.selection):
        sel_ind = self.selection.index(ch_name)
        self.selection.pop(sel_ind)
        this_alpha = self.alpha_other
    else:
        self.selection.append(ch_name)
        this_alpha = 1
    self.fc[(ind, (-1))] = this_alpha
    self.collection.set_facecolors(self.fc)
    self.canvas.draw_idle()
    self.canvas.callbacks.process('lasso_event')
