Attaching data

Simulating data is great for seeing how models might look when measured by a reflectometer, but mostly we are going to use the program to fit measured data. We saved the simulated data from above into files named nifilm-tof-1.dat, nifilm-tof-2.dat, nifilm-tof-3.dat and nifilm-tof-4.dat. We can load these datasets into a new model using nifilm-data.py.

The sample and instrument definition is the same as before:

from refl1d.names import *

nickel = Material("Ni")
sample = silicon(0, 5) | nickel(100, 5) | air

instrument = SNS.Liquids()

In this case we are loading multiple data sets into the same ProbeSet object. If your reduction program stitches together the data for you, then you can simply use probe=instrument.load('file').

files = ["nifilm-tof-%d.dat" % d for d in (1, 2, 3, 4)]
probe = ProbeSet(instrument.load(f) for f in files)

The data and sample are combined into an Experiment, which again is bundled as a FitProblem for the fitting program.

M = Experiment(probe=probe, sample=sample)

problem = FitProblem(M)

The plot remains the same:

(Source code, png, hires.png, pdf)