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1 vote
1 answer
934 views

Finding the parameters of a function via curve fit

I'm trying to estimate the parameters (v, n, k) defined in fit_func. I tried the default least squares fit but I couldn't find the parameters successfully. ...
Natasha's user avatar
  • 433
0 votes
0 answers
43 views

I would like to fit a data to integral type model but cannot figure it how?

I have cumulative data for concentration versus time. I would like to fit the following model to the data: $$\frac{1}{\Gamma(n) \bar{t}}\int_{0}^{\frac{n t}{\bar{t}}}z^{n-1} e^{-z}dz$$ $n$ and $\bar{...
isar charmchi's user avatar
3 votes
2 answers
225 views

Optimization of known function with respect to two unknown function arguments

I have a data set, composed of points $(x_i, y_i)$ for $i=1,N$. I also have a known function $F$, which maps these points $x_i$ to $y_i$ as such $F(x_i, a(x_i),b(x_i)) = y_i$, where $a(x_i)$ and $b(...
gammapoint's user avatar
0 votes
3 answers
256 views

Choice of solver/software for global optimisation of cheap black-box function with known derivatives

I am trying to estimate a few unknown parameters of my continuous non-linear PDAE model (simulated through finite-volume method spatial discretisation, and time-stepping through method-of-lines). I am ...
Dr Krishnakumar Gopalakrishnan's user avatar
1 vote
1 answer
295 views

Fit curve with rectangles

I have a one-dimensional set of points, i.e. $(n,y_n), 1\leq n \leq N$. I want to fit them with a linear combination of $k$ rectangular functions in a least-squared-error sense. Each rectangle is ...
Milind R's user avatar
  • 607
2 votes
0 answers
61 views

Inverted value is not consistent with expectation

We have a group of observations $$y = f(x_1, x_2, x_3) \enspace .$$ We have also a forward model $y = f(x_1, x_2)$. The forward model does not include $x_3$ because $x_3$ might include dozens of ...
Ting Yang's user avatar