def add_line(self,fig,axis,params,name,colour):
        x_max = np.max(self.train_X)
        x_min = np.min(self.train_X)
        x = np.arange(x_min,x_max,0.1,dtype = "float")
        y_star = ((params[1,1]-params[1,0])*x + (params[0,0] - params[0,1]))/(params[2,0] -params[2,1])
        axis.plot(x,y_star,'g--',c=colour, label=name, linewidth=2)
        axis.legend()
#        fig.show()
        return fig,axis
dataset/ETHPy150Open alvations/pywsd/merlin/simple_data_set.py/SimpleDataSet.add_line/swapped operands of `-`