POLYFIT

evaluates polynomial fit on data in a piecewise manner

<IN>    - Type 1000/2000 format S# input file name. 
<ORDER> - Order of polynomial [DEF=1]
<COEF>  - Results label to receive coefficients
<OUT>   - Output file name to receive fit coefficients.Type 2000 format SD.
<FIT>   - Output file name to receive fit output. Type/Format of <IN>.
<ERR>   - Output file name to receive error output. Type/Format of <IN>.

The <IN> file can be a type 1000 or 2000 file.  If 1-D file, POLYFIT will fit
one curve to the entire file.  If 2-D, POLYFIT will fit one curve to each frame
of the input file.  The output files follow the input file type.

The internal algorithm normalizes the abscissa to be from 0 to 1 to prevent
floating point overflow errors when XSTART or XDELTA are large numbers.  The
coefficients are transformed to the file's abscissa reference frame before
output.

All internal statistics and matrix transformations are computed in double 
precision regardless of input data type.

Examples:

Switches: NONE