Linked Questions

1 vote
1 answer
2k views

How do I fit NDSolve result to experimental data? [duplicate]

I have two coupled ordinary differential equations which I solve numerically in Mathematica, but now I want to fit the solution with experimental data. I do following, (the experimental data ...
nitin's user avatar
  • 253
2 votes
0 answers
859 views

How I can use FindFit to simultaneously fit two data sets to two equations having shared parameters? [duplicate]

I think that FindFit package with the method Nminimize yields global minimum if initial values of adjustable parameters are ...
Mousa Jafar's user avatar
0 votes
0 answers
449 views

Performance in parameter estimation from ParametricNDSolve using varied initial conditions [duplicate]

I have 250 data points from a timecourse exeriment in a list, with columns specifying (1) time, (2-4) initial conditions, (5) absorbance reading. I want to fit 4 parameters (k1, k2, k3, k4) in a DAE ...
user avatar
4 votes
0 answers
325 views

Using FindFit to fit nonlinear ODE parameters, subject to a constraint (an inverse problem) [duplicate]

Similar to this post I am finding that constraints tend to make FindFit poor at finding a good fit. However, unlike the previous post, the constraints are required ...
Stretch's user avatar
  • 141
0 votes
0 answers
291 views

How to fit data with numerical solution of system of parametric ODE? [duplicate]

I need to find the parameters (k1,k2,k3,k4,k1r,k2r,k3r,k4r) that fit my data (list of [Intensity, time]) using the function <...
Irene's user avatar
  • 1
2 votes
0 answers
219 views

Simultaneous fitting to multiple data sets with multiple variables and some common parameters [duplicate]

I am trying to fit two data sets to a function model described below which share a few common parameters. Say I have two functions with some common parameter(s) ...
Arijit's user avatar
  • 21
6 votes
3 answers
1k views

How to fit parameters in a system of coupled differential equations

Problem description: I'm studying a chemical reaction that can be modeled by a system of coupled differential equations, and I want to use measured data to determine the parameters that appear in the ...
P. B.'s user avatar
  • 243
9 votes
1 answer
669 views

Can I use a differential equation as a model to make a fit to experimental data?

I've done an experiment where I swung a pendulum under air resistance. Is it possible to model the data using the following differential equation and find a b-value? ...
fidafa123's user avatar
  • 145
9 votes
1 answer
2k views

ODE fitting to dataset

So, I have a ODE system, it is a complex biochemical kinetic mechanism with six species changing over time. ...
BlueOysterCult's user avatar
5 votes
2 answers
1k views

Non Linear Model Fit - Fitting ODE to Data

Thank you everyone for your meaningful contributions! My Goal and Problem I'm trying to fit a particular ODE in a set of ODE's to experimental data. I've attempted to implement this by following the ...
user3741793's user avatar
5 votes
2 answers
1k views

FindFit “is not a real number” error when fitting a parametric function to the data

I am using Mathematica's FindFit function to fit a parametric solution to my data and I am getting the error ...
Sam's user avatar
  • 53
4 votes
2 answers
486 views

Multi-Fitting with Nonlinear model

I want to fit experimental data by the H-N model. Here is the H-N model: $$\text{EHN}(T)\text{=}\text{E$\infty $}+\frac{\text{E0}-\text{E$\infty $}}{\left(1+\left(i \omega\tau(T_g)10^{-\frac{\text{C1} ...
Yuuhsing Tuan's user avatar
6 votes
1 answer
832 views

Chemical Kinetics: fitting multiple sets of time series data using multiple differential reaction equations

Let me start by saying that this is my first post, so if there are suggestions on proper formatting that is annoying you, please let fly and I will do my best to modify. I was doing well solving the ...
Rob the Chemist's user avatar
4 votes
2 answers
426 views

Modeling experimental data with differential equations

I have the following two sets of experimental data, which show the dependencies of two quantities, namely, $S$ and $B$, on time ($0$ h, $3$ h, $6$ h, $9$ h, $15$ h, $18$ h, $21$ h, and $24$ h): ...
user avatar
4 votes
2 answers
1k views

FindFit for a differential equation model with multiple variables?

I'm trying to figure out how to use FindFit with a multivariable differential equation model and data. I've successfully made it work for the one-variable version ...
dantimatter's user avatar
1 vote
2 answers
759 views

How to Fit experimental data with 4D ParametricNDSolve?

Let me first explain the background problem. I'm trying to solve a problem with a projectile motion in 4D such that the position vector is: $\boldsymbol{r}(t)=\boldsymbol{r}[x(t),y(t),z(t)]$ I have ...
user3142983's user avatar
1 vote
2 answers
330 views

Minimize the sum-of-squares errors for a system of ODEs

I'm trying to minimizing the sum of squared errors on a 2-equation system of ODEs and empirical data. I keep getting an error and I think the root of the problem is my invocation of ...
E3labs's user avatar
  • 485
2 votes
0 answers
1k views

ParametricNDSolveValue or NDSolve + fitting

I have been trying to find the value for the parameter kestim that yields the best fit of a model to some data points. datac has ...
Sos's user avatar
  • 2,168
3 votes
2 answers
569 views

How do I find the best fit?

I am trying to solve following system of three differential equations ...
Lolek's user avatar
  • 31
0 votes
1 answer
905 views

Exporting tables of interpolating functions

A few weeks ago I asked a question about manipulating parameters in NDSolve (Looping with NDSolve?) , and received some very helpful advice about the manipulate environment; now I want to take the ...
DRG's user avatar
  • 877
5 votes
1 answer
150 views

Getting errors in NonlinearModelFit

I need to fit a system of ODEs to data. The solutions which could work for me are given in the following posts How to fit 3 data sets to a model of 4 differential equations? ODE fitting to dataset ...
Ganna Rozhnova's user avatar
4 votes
1 answer
317 views

How do I get the MeanPredictionBands from the fitting of the numerical solution of coupled differential equations to data?

This is my first post, and I will preface my question by stating that I am relatively new to Mathematica. In any case, I would like to fit the solution of chemical kinetics equations to data and get ...
Rischaard's user avatar
1 vote
1 answer
634 views

Dsolve too slow -- is there anyway around?

I am trying to solve: ...
Weiwei's user avatar
  • 11
1 vote
1 answer
345 views

non linear Least Squares with model function given by ODE's

I have to fit to experimental data a model function given by a linear combination of functions y1(t) and y2(t) a1*y1(t) + a2*y2(t) with a1 and a2 ...
francesco's user avatar
0 votes
1 answer
233 views

How to adjust excel data for NonlinearModelFit?

I'm really new to Mathematica and I'm facing a problem and would really appreciate some help! Maybe my question is similar to one described in How to fit 3 data sets to a model of 4 differential ...
OlgaE's user avatar
  • 21
1 vote
2 answers
118 views

Step size issue with ParametricNDSolveValue to fit data to a set of non linear differential equations

I am fitting dataset dset to a set of non-linear differential equations to find the fitting parameters dP (pressure differential)...
Ali Hashmi's user avatar
  • 9,000
3 votes
0 answers
242 views

How to fit two datasets with common fit parameters?

I have two data sets which go: ...
D.Anishchenko's user avatar
0 votes
0 answers
225 views

Problem fitting ODEs to data using NonlinearModelFit with ParametricNDSolveValue

The following code attempts to fit a system of differential equations (enzyme kinetics) to some data, which for now happens to be fake data extracted from a solution with a particular set of ...
HappyTreeFriend's user avatar
0 votes
1 answer
223 views

NonlinearModelFit with of a single PDE parameterized several times

Edit: My approach was wrong, I have solved this - please see comments I've been scouring the answers and the docs but I'm having trouble figuring out the answer to this one. In particular, Olksander ...
Jake M's user avatar
  • 1
1 vote
0 answers
124 views

How to fit 3 data sets to a model of 3 differential equations?

I want to fit 3 data sets to a model consisting of 3 differential equations and 7 parameters. I want to find the parameters best fitting to my model. I have searched for several related examples. I ...
王晗青's user avatar

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