I'm using a quite large grid for creating a interpolant (with TriScatteredInterp) that I can then sample at some other points of interest. The TriScatteredInterp object takes a while to form, so instead I decided to save it once as a .mat variable and load it instead of creating it every time I run the code. However, to load the 14.2 mb MAT file takes 34 seconds! Why is this? Forming it anew takes 35 s, so I might as well just do that every time. Loading a normal matrix from a .mat file is usually very fast..