Synopsis
		sfbigmpiencode encode=Fencode.rsf nx= ny= dy= dx= ox= oy= verb=n dprefix= eprefix= shots=

Use mpiencode if your shots are on the same grid prior to encoding.

Use bigmpiencode if your shots are not on a single grid prior to encoding.
YOUR SHOTS MUST ALL FALL ONTO THE SAME REGULAR GRID. BigMPIENCODE does not do any
shot interpolation.

Data axes - X, Y, W

Parameters
		string dprefix= printf like statement that can be evaluated to find the data files corresponding to shot records   float dx= dx of output grid points   float dy= dy of output grid points   file encode= auxiliary input file name   string eprefix= printf like statement that can be evaluated for the output encodings   int nx= # of output grid x points   int ny= # of output grid y points   float ox= ox of output grid points   float oy= ox of output grid points   string shots= shot-file name, dimensions are 1xNS   bool verb=n [y/n]