Dataset of input-output pairs of functions governed by Darcy's law, which describes flow through a semiporous medium. The data is saved as keyed pairs of PyTorch Tensors. Inputs (keyed 'x') are a(x), the input function that describes the diffusivity constant at each point on the discretized domain. Outputs (keyed 'y') are u(x), the solution function that describes the flow at each point on the domain. Available discretized resolutions: 16x16, 32x32, 64x64, 128x128, 421x421.