pwiselinterp
finds a piecewise linear function that
interpolates the data points. For each x-y ordered pair, there
function finds the unique line interpolating them. The function will
return a data.frame with three columns.
The column x
is the upper bound of the domain for the given
piece. The columns m
and b
represent the coefficients
from the y-intercept form of the linear equation, y = mx + b.
The matrix will contain length(x) rows with the first row having m
and b of NA.