Help for XFORM

 "XFORM" will perform a linear transformation on the input data.
 The transformation is specified  by a matrix input as a 
 parameter. If desired, XFORM will scale the output to a user
 specified range, which defaults to the full range of the data 
 type. (XFORM will now accept a parameter dataset as input)

 EXECUTION:

 XFORM (INP1,INP2,...) (OUT1,OUT2,...) SIZE PARAMS          or
 XFORM  INP            (OUT1,OUT2,...) SIZE PARAMS          or
 XFORM (INP1,INP2,...)  OUT            SIZE PARAMS          or
 XFORM  INP             OUT            SIZE PARAMS          or

 OPERATION:

 Let each corresponding pixel from the input data sets be
 represented by a vector x[T] = (x1,x2,...xm)[T], where [T}
 denotes Transpose. Let A be the parameter matrix (n * m).
 Then XFORM computes the product:

 AX = V

 A gain and offset are then applied to each component before
 it is written to the output data set:

 V'(i) = P(i)  + Q(i).V(i)

 Auto-scale mode is the default condition if gains and offsets
 are not specified using preset or gain/offset.
 In auto-scale mode, the gains and offsets for each band are
 calculated by fitting the output histogram to user - specified
 parameters. This calculation requires a separate pass, which 
 can double the computation time.

 RESTRICTIONS:

 Currently, the program limits NI and NO to 32 because the relevant
 arrays are dimensioned to that size.

 XFORM WRITTEN BY:  J.D.Addington,  Jan. 1977

 XFORM CONVERTED TO VAX BY:  F.F.Moss, Jan. 1984

 XFORM WRITTEN BY:  L.W.Kamp,  Sept. 1984

 CONVERTED TO VICAR2 BY:  J.H.Reimer, July 1985

 REWRITTEN IGNORING AP COMPATIBILITY: Ron Alley, June 1986

 CURRENT COGNIZANT PROGRAMMER:  Ron Alley