convert normal string to latex string to use in matplotlib

Question

So I know that if I want to use a LaTeX string in my plots I should instead of for example \"sin(x)\", I should use r\"\\sin(x)\".

But if I hav

Answer 1

Use a = r"$\sin (x)$" Or alternatively convert variable a to b, like so:

import matplotlib.pyplot as plt
ax = plt.gca() 
x = [1,2,3,4,5,6]  
y = [324,456,6,78,2,54]  # cramming numbers on my keyboard
a = "\sin(x)"
b = r"$"+a+"$"
ax.plot(x, y, label=b)

ax.legend()
plt.show()

Answer 2

Mind that to have MathText activated the string must be in between Dollar signs ($).

In case your latex contains backslashes you need to either use a raw string from the beginning

a = r"$\tan(\nu\cdot x)$"

or escape the backslashes

a = "$\\tan(\\nu\\cdot x)$"

If you try something like in the other answer, you'd get unexpected results

a = "\tan(\nu\cdot x)"
b = r"$"+a+"$"
ax.plot(x, y, label=b)

results in