Help for IBISLSQ2

PURPOSE

   "ibislsq2" performs 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.


EXECUTION

     ibislsq2 INP=DATA.INT  INDCOL=(1,2,3) DEPCOL=4 CONCOL=7  	     RESCOL=8  COEFFCOL=(21,22,23) 'NOPRINT

    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 are 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.  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 length of each set should, of course, be longer than the
number of independent variables (columns).  If it is not then the
least squares fit will not be called and values of -999.0 will be
put out for the solution.  If some columns of the independent data
are dependent then the error MATRIX RANK TOO SMALL be be printed,
and -999.0's will be put out for the solution.  If there is no
solution then zeros will be put out for the residuals.



EXAMPLES

   Suppose that columns 1 and 2 contain points (x,y) in a plane 
   and  column  7 contains a function  f(x,y).   The  following 
   sequence  will perform a quadratic least squares fit  h(x,y) 
   and place the residuals in column 8.

   mf INP=A FUNCTION=("C3=C1*C1","C4=C2*C2","C5=C1*C2","C6=1")
   ibislsq2 INP=A INDCOL=(1,2,3,4,5,6) DEPCOL=7 RESCOL=8


RESTRICTIONS

The maximum number of independent columns (variables) is 20.

Original Programmer: A. L. Zobrist, 11 Sep, 2001
Current Cognizant Programmer: A. L. Zobrist

REVISIONS
  2002-08-27 A. L. Zobrist
  2008-01-03 W. L. Bunch Switched to USES_ANSI_C AND LIB_CARTO; misc cleanup
  2015-11-02 W. L. Bunch Migrated to MIPL