Integrating a Single Term in A PDE

variational formulation
1

I have a term ‘A’ in one of my PDEs, however I only have an equation defining the derivative, dA/dx. I can manually integrate with respect to x, but it gives me an extremely long and complex equation to type in. Is there a simpler method in FEniCS to find A?

Many thanks!

2

Without knowing what A is (a scalar or vector or tensor or …), you could try using FEniCS to numerically solve a one-dimensional ODE along the lines of:

A(x) = A(0) + \int_0^x \frac{dA}{d\hat{x}} d\hat{x}

3

Thank you so much for your reply, but I’m afraid I’m still a bit confused. As a ‘toy’ example, if dA/dx was defined as:

dA/dx= (8x-x^2)/(3 ln x)

how would I input that into the code?

Thanks again!