L-curve
L-curve is a visualization method used in the field of regularization in numerical analysis and mathematical optimization. It represents a logarithmic plot where the norm of a regularized solution is plotted against the norm of the corresponding residual norm. It is useful for picking an appropriate regularization parameter for the given data.
This method can be applied on methods of regularization of least-square problems, such as Tikhonov regularization and the Truncated SVD, and iterative methods of solving ill-posed inverse problems, such as the Landweber algorithm, Modified Richardson iteration and Conjugate gradient method.