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-- nonlinear least-squares fitting
import Numeric.GSL.Fitting
import Numeric.LinearAlgebra
xs = map return [0 .. 39]
sigma = 0.1
ys = map return $ toList $ fromList (map (head . expModel [5,0.1,1]) xs)
+ scalar sigma * (randomVector 0 Gaussian 40)
dat :: [([Double],([Double],Double))]
dat = zip xs (zip ys (repeat sigma))
expModel [a,lambda,b] [t] = [a * exp (-lambda * t) + b]
expModelDer [a,lambda,b] [t] = [[exp (-lambda * t), -t * a * exp(-lambda*t) , 1]]
(sol,path) = fitModelScaled 1E-4 1E-4 20 (expModel, expModelDer) dat [1,0,0]
main = do
print dat
print path
print sol
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