A method of generating a stream of non-contiguous memory addresses representing contiguous points in logical space is described. The method comprises: generating initializing parameters describing the contiguous points in the logical space; configuring a memory address engine with the initializing parameters; performing an algorithm in the memory address engine according to the initialising parameters to produce a plurality of non-contiguous memory addresses; and collating the non-contiguous memory addresses into the stream of memory addresses for output to a data memory. The present invention has particular application to SIMD processing techniques where there are a plurality of memory address engines.