D. Melgar 05/2013

This code performs baseline corrections to accelerometer data 
using 1 of 6 methods:
* Fit a piece wise linear function (Boore)
* Fit a quadratic (Boore)
* High pass filter the data then integrate
* Use static field constraint analytically
* Use static field constraint with grid search
* Fit a step function, with or without static field constraints

There are some extra references in the code you can look at and
for a detaield discussion of the pros and cons of the methods and
if you use this code please look at and reference:

Melgar, D., Y. Bock, D. Sanchez, and B.W. Crowell (2013), On robust 
and reliable automated baseline corrections for strong motion 
seismology, J. Geophys. Res., 118, doi: 10.1002/jgrb.50135