Program sfaxplusy | Computes a*x + y, where x and y are datasets, and a is scalar

[SYNOPSIS]
sfaxplusy < in.rsf y=yfile.rsf > out.rsf afile=fa.rsf a=1 verb=n
[COMMENTS]
x and y are floats or sf_complex, single precision
x is the stdin
a is double precision
Computations are done in double precision. 
[PARAMETERS]
double  | a | =1 |   | 	Scaling factor 
file    | afile | = |   | 	auxiliary input file name
bool    | verb | =n |  [y/n] | 	Verbosity flag 
file    | y | = |   | 	auxiliary input file name
[DIRECTORY]
user/jeff
