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Alex Sha


82 total contributions since 2019

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  • 6 Month Streak
  • Knowledgeable Level 2
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Answered
How to curve fit following summation equation in MATLAB with given experimental data.
Hi, Yadav, I actually use a software package other than Matlab, named 1stOpt, it is much easy for using without guessing initial...

4 days ago | 1

Answered
How to curve fit following summation equation in MATLAB with given experimental data.
d(K/ (1+exp(c-b*t)))/dt=k*exp(c-b*t)*b/sqr(1+exp(c-b*t)),so your fitting function become: is the above correct? if yes, you m...

5 days ago | 0

| accepted

Answered
How to curve fit following summation equation in MATLAB with given experimental data.
Hi, Yadav, in your function "a*d/dt(k/1+exp(c-b*t))", what is "d/dt"? does "k/1" equal to "k"? Please describe clearly.

6 days ago | 1

Answered
Least square curve fit
The function of lsqcurvefit use local optimization algorithm, so it is too weak on fault tolerance, try to use global optimizati...

10 days ago | 0

Answered
lsqcurvefit for global fitting gives bad parameters
Hi, I have just try to solve this complex fitting problem by using another math package, the result is as following, seems to be...

13 days ago | 0

Answered
How to fit a quadratic equation to the experimental data by manipulating quadratic coefficients?
If you don't care the type of fitting function, try the following one: y = p1+p2*x+p3*x^3+p4/x+p5/x^2 Sum of Squared Residual:...

15 days ago | 0

Answered
Exponential fit by customised equation
Hi, Sushreesmita Mishra, the problem you met is normal. When chose build-in function for data fitting, since "build-in", so Matl...

17 days ago | 0

| accepted

Answered
Problem by star values lsqcurvefit
Hi, Zuyu An, what's your exact data? xdata = [0 0.005 0.01 0.015 0.02 0.025 0.03 0.035 0.04 0.045 0.05 0.055 0.06 0.065 0.07 0....

27 days ago | 0

Answered
lsqcurvefit fitting not good
whether fminsearch or lsqcurvefit in Matlab use local optimization algorithms, it is why the initial start values are so importa...

28 days ago | 0

Answered
Fitting Monod Equation with ODE45 to data using lsqcurvefit function
Hi, Vinoj Liyanaarachchi, the code have been provided above alreadly, but note, that code is not for Matlab, but for another pac...

28 days ago | 0

Answered
Fitting Monod Equation with ODE45 to data using lsqcurvefit function
The follow results obtained from 1stOpt may be used for comparison: Code: Variable t,x,s,p; ODEFunction x'=umax*s*x/(ks + s);...

28 days ago | 0

Answered
curve of best fit from a few points
The equation below is good enough: y = p1+p2/(p3-x)^2; Root of Mean Square Error (RMSE): 0.000924797017843405 Sum of Squared ...

29 days ago | 0

Answered
What function fits my data...?
The follow function is much simple, but more better: y = x/(p1+p2*x)+p3 Root of Mean Square Error (RMSE): 0.313525722040886 S...

1 month ago | 1

| accepted

Answered
Curve fitting by Genetic Algorithm
Rerfer the results below: Root of Mean Square Error (RMSE): 0.00353350868235726 Sum of Squared Residual: 0.00029965640659906 ...

1 month ago | 1

Answered
Fsolve- equation solved, inaccuracy [possible
If want all are positive, refer the results follow: x1: 0.0990335590812945 x2: 1.27592369827812E-11 x3: 650.000000000022 x4:...

1 month ago | 0

Answered
fitting scatter data into multiple cosine functions
So, an gao, what is the result you want? Unless you add range constraint for all parameters (except w), because there are trigon...

1 month ago | 0

Answered
fitting scatter data into multiple cosine functions
Hi, how about the results below, the fitting is perfect, the reason for you cann't get good result is more possible the bad init...

1 month ago | 0

Answered
Data fitting to the solution of coupled differential equation with all the different parameters.
if take initial conditions as: t=30,n=0.1178512,i=0; Root of Mean Square Error (RMSE): 0.00101378248364856 Sum of Squared Resi...

1 month ago | 0

Answered
Is it possible to provide initial guesses in cftool?
Yes, it is possible if using global optimization algorihms (the curve fitting functions built in Matlab, i.e. cftool, lsqcurvef...

1 month ago | 0

Answered
How to solve 4 equations with 4 unknowns using matlab
r1: 0.0269466666666667 r2: 2153.11111111111 r3: 2523.94560037811 r4: -2522.97254704477

1 month ago | 0

Answered
How to solve 5 equations with 5 unknowns
Numercial solution: a: 9.00473933649289 b: 1.18483412322275 c: 3.55450236966825 d: 1.54545454545455 e: 17.2

1 month ago | 0

Answered
How do I fit multiple curves with same fitting parameters?
How about the results follow: Parameter Best Estimate -------------------- ------------- b1 -1.42830819954452 b2 5...

1 month ago | 0

Answered
Lsqcurvefit / Lsqnonlin to electrical model. Bad fit problem
Have a try with the results as below: Parameter Best Estimate -------------------- ------------- x1 30060.922855124...

1 month ago | 0

Answered
Fit function and uncertainty
Hi, attach your data file please, if possible.

1 month ago | 0

Answered
Fitting Data for the given equations below?
seems too complicated for Matlab, the follows are the code of 1stOpt, another software package: Constant RT = 8.314E+3*299; Pa...

1 month ago | 0

Answered
Solve function with equations and inequations
There are too many numerical solutions: 1: x_1: 0.0219289963140093 x_2: -1.20176285580936 x_3: -33.4147964294915 x_4: 194.3...

1 month ago | 0

Answered
Damped harmonic motion curve fit
The fellow results are little better. Parameter Best Estimate ---------- ------------- b1 -1.36099782974822 b2 -599.11082464...

1 month ago | 0

Answered
Parameter identification with nlgreyest
Hi, would you please attach your data.

1 month ago | 0

Answered
Data fitting to the solution of coupled differential equation with all the different parameters.
Hi, Vira Roy, attached your data please, if possible.

1 month ago | 0

Answered
distribution fitting to data
Hi, you could try the combination of three Gauss function like below Root of Mean Square Error (RMSE): 2.2458311950253 Sum of ...

1 month ago | 0

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