matplotlib, including more than one defined variable on legend label

Question

Im trying to include two or more variables, previously defined in the code, to the label for the legend or when plotting text. For example, I have a bunch of functions plotted and I want the equations for each on the legend. If I just have something like y = Ax, where A is found by fitting a function to some data I would write something like:

 plt.plot(x, y, label='y = %.2f x' %A) 

and on the legend I would see the real value of A on the equation. Now if I want to do the same with y = Ax + B and I go

 plt.plot(x, y, label='y = %.2f x + %.2f' %A %B)

I get an error. Most of the ways I tried gave me syntax error and I got one that said not enough arguments for format string.

Answer 1

Try this

 plt.plot(x, y, label='y = %.2f x + %.2f' %(A, B))

Answer 2

As an alternative, you can use the more flexible python string formatting using the .format() method. For example:

 plt.plot(x, y, label='y = {0:.2f} x + {1:.2f}'.format(A,B))