Given the values and lefthand endpoints for intervals of constancy, lookup values of the function at arbitrary values of the independent variable.
lookup(xgrid, ygrid, x, y0 = 0)
~Describe the value returned If it is a LIST, use
Description of 'comp1'
Description of 'comp2'
Lefthand endpoints of intervals of constancy
Values on these intervals, of same length as xgrid
Input vector of arbitrary independent variables.
Value to be returned for values of x
that are smaller
than min(xgrid)
.
Grant Izmirlian <izmirlian@nih.gov>