[Numpy-discussion] "upsample" or scale an array

I need to take an array - derived from raster GIS data - and upsample or scale it. That is, I need to repeat each value in each dimension so that, for example, a 2x2 array becomes a 4x4 array as follows: [[1, 2], [3, 4]] becomes [[1,1,2,2], [1,1,2,2], [3,3,4,4] [3,3,4,4]] It seems like some combination of np.resize or np.repeat and reshape + rollaxis would do the trick, but I'm at a loss. Many thanks! -Robin