Help for IBISLSQF

PURPOSE

   "ibislsqf" performs linear least squares fits on data in
an IBIS interface (tabular) file.  The solutions and/or residuals
can be placed in specified columns of the file.  The solutions can
also be output to the terminal.  Multiple fits can be done on
different parts of one file.

The program features data handling for functions that are too complex
to handle with other IBIS programs such as ibislsq2 and mf3, etc.
The particular case is RPC function handling (RPF).

The solcol applies to the second ibis file. The first column can be
a guess solution vector and can be a superset of the variables that
are actually being solved for.  The final solution is output to the
second column named in solcol.  The remaining column is for testing
purposes and checks the solution.  In the RPC case, the program is
solving for the solution as a subset of the solution vector (for example
it can be solving for only the x,y terms and not the height terms.

The coefficients in the solution may be a subset of the coefficients in
the solution vector.  This is useful for the RPF cases, see especially
RPC10N and RPC12N.  The user must then program for transfers from the
coefficient vector to the guess vector in two places:

1.  Setting up the guess vector in the main program.
2.  Transferring one solution step in the subroutine TEST_FDF.

The PPC functions: "RPCN20","RPCN10","RPCN11","RPCNZT","RPCNZ2"

RPCN20 - solves for the 20 numerator coefficients
RPCN10 - solves for the 10 numerator coefficients not involving
         the Height term
RPCN11 - solves for the 10 numerator coefficients not involving
         the Height term, plus the single H^1 term
RPCNZT - solves for the 10 numerator coefficients that involve Height
         holding the x,y terms constant, the numerator constant also
         varies
RPCNZ2 - solves for the numerator H^1 coefficient that involves Height
         holding all other terms constant, the numerator constant also
         varies
RPCNZ1 - solves for the numerator H^1 coefficient that involves Height
         holding all other terms constant, the numerator constant is held
         fixed
RPCROLL- solves for the numerator H^1 coefficients for both line and sample
         directions constrained to be in the direction of roll.  The
         numerator constants are held fixed

EXECUTION

     ibislsqf INP=(DATA,GUESS) FUNC=RPCN20 DATACOL=(1,2,3) DEPCOL=4 CONCOL=7  	     RESCOL=8  COEFFCOL=(21,22,23,24,25) 'NOPRINT SOLCOL=(1,2,3,4,5)

    This example shows the use of all of the parameters.  The input
file, DATA.INT, is an IBIS interface file.  The data for the independent
variables is in columns 1,2,3 and the data for the dependent 
variables are in column 4.  The control column 7 is used for
multiple fits to be done in one run.  The least square fits are done 
on sets of rows; a new set is started whenever the value in the control 
column changes.  If no control column is specified then one fit
is done on the whole file.  The COEFFCOL and RESCOL parameters specify
in which columns, of the input file, the results will be put.  If either
or both are not specified then they will not be output.  There must be
as many coefficient columns as there are independent columns and these
match the sequence of the independent variable columns.  The
coefficients of the solution are placed in columns 21,22,23,24,25.  The
residual column can be used to easily calculate the deviation of the
data points from the fitted line. Normally the solution for each set
is printed to the terminal, but this can be turned off with the
'NOPRINT keyword.  The second input file is an IBIS interface file contain-
ing the guess in column 1, solution output into column 2, and testing values
in the other three columns.

    The length of each set should, of course, be longer than the
number of independent variables (columns).  If it is not then the
routine will still probably find a feasible solution (usually not unique)
and go on.


RESTRICTIONS

The maximum number of independent columns (variables) is 20.  Note
that all of the RPC routines use 3.

Original Programmer: A. L. Zobrist, 18 Apr, 2005
Current Cognizant Programmer: A. L. Zobrist
Last changed by: A. L. Zobrist, 18 Apr, 2005
Revisions:
  Fri Dec 28 2007 wlb switched to USES_ANSI_C AND LIB_CARTO; misc cleanup
  2022-08-10 B. Crocco afids to opensource (untested)

PARAMETERS: