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Alex Sha


31 total contributions since 2019

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Answered
Curve fitting tool with 4 variables
Attach your data file please.

ongeveer 6 uur ago | 0

Answered
Improving fit of custom function
Hi, what is the function you want to fit? y= A+m*x+(B+n*x)/(1+10^(-((x-C)/D))) or y= A+m*x+(B+n*x)/(1+exp(-((x-C)/D))) if th...

ongeveer 6 uur ago | 0

Answered
continuity of a fit function in different regions
Hi, the tool I used is "1stOpt",an Independent software (not the toolbox or command of Matlab), the full codes have been provide...

ongeveer 11 uur ago | 0

Answered
continuity of a fit function in different regions
Hi, use the function above, p1 and p2 are two divided point, the solve tool is 1stOpt, code: Parameter p1=[0,1],p2=[1,2]; Fu...

1 dag ago | 0

Answered
continuity of a fit function in different regions
Attach your data file please.

1 dag ago | 0

Answered
Solving Multivar Non-Linear Regression from a Data Set
not Matlab, another software named "1stOpt"

1 dag ago | 0

Answered
Fit convergence to degenerated model - a reasonable expectation?
we use a software called "1stOpt"

1 dag ago | 0

Answered
Fit convergence to degenerated model - a reasonable expectation?
Hi,Dev-iL,theoretically,the SSE of f2 should be less or equal to that of f1, since f1 is the special case of f2, when b3=0. Als...

1 dag ago | 0

Answered
How to solve 4 equations with 4 unknowns with bounds?
Refer the results below: x1: 7.73410323214524 x2: 32.0801819920043 x3: 33.4573119565274 x4: 11.2688338748665

8 dagen ago | 0

Answered
Solving Multivar Non-Linear Regression from a Data Set
try the function below: z = (p1+p2*x+p3*y)/(1+p4*x+p5*y)+p6; where z: moisture content; x: temperature; y:humidity Root of Me...

17 dagen ago | 0

Answered
Fit convergence to degenerated model - a reasonable expectation?
Hi, I think you may make wrong calculation: with function of "f1(T) = A/( exp(B1/T + B2/T^2 ) + C )", the result is: R...

17 dagen ago | 0

Answered
solve a system of equations
There are multi-solutions: 1: x: -4.93419751895286 y: -16.1073500969731 r: 327.876127534353 2: x: -3.55619697118012 y: -8...

19 dagen ago | 0

Answered
fmincon with nonlinear equality constraints
Please try a software called "1stOpt": Codes: MinFunction x1+x2+x3+x4+x5+x6+x7; (1-x1)*(1-x2)=0; (1-x1)*(1-x2)*(1-x3)*(1-x6)...

19 dagen ago | 0

Answered
How can i linearise this equation in matlab? y=a*x*e^b*x
by linearization, the results are: a: 9.66178585962543 b: -2.47330876570272 While if using nonlinear regression fitting direc...

24 dagen ago | 0

Answered
How to use multistart with 'fit' function
Multi-solutions (Parameter a is different): 1: Root of Mean Square Error (RMSE): 0.109662308225183 Sum of Squared Residual: 0...

25 dagen ago | 0

Answered
How to fit data to a Weibull bi-modal function ? nlinfit? lsqcurvefit?
please refer the results below: c1 6.93726775107201 c2 2.61789361078231 c3 5.06299442732144 c4 4.41925787462909 or: c1 5.0...

26 dagen ago | 0

Answered
Curve Fitting for Forced Damping
Where are your data?

26 dagen ago | 1

Answered
Fitting multiple Datasets with shared and individual Parameters.
Hi, Fabian Bienen, if possible please upload your data here, I may try to solve it.

26 dagen ago | 0

Answered
Line search algorithm: nonlinear least squares method for fitting experimental data to a model
Please upload your data,I may try.

26 dagen ago | 1

Answered
fitting a parabola giving unreasonable answer
Note the part "b.*6.022e23" in the fitting function y = a.*exp(((-4.*pi.*b.*6.022e23)./(8.314.*1623)).*(((c./2.*(c-x).^2) - (1/3...

26 dagen ago | 0

Answered
fsolve message "Equation solved, inaccuracy possible"
if x should be positive, then the solution 1 should be answer. I use another software "1stOpt", the code is very simple as below...

26 dagen ago | 1

Answered
Non Linear Fit help?
For the fitting function: F = (((K.*(Vg-V).^(b+1)).^(-1))+R).^(-1); Obviously,should be: V < min(Vg) = 0, the reuslt may be: ...

28 dagen ago | 0

Answered
Parameter estimation using fminsearch and ode45
The "true" Global Optimization Algorithm does not need to guess initial start values of parameters, unfortunately, most of curre...

28 dagen ago | 0

Answered
fsolve message "Equation solved, inaccuracy possible"
Multi-solutions: 1: x1: 1.00788811123075E-6 x2: 0.0083586258586415 x3: 0.0330975342164431 x4: 0.000243072462467804 x5: 4.2...

ongeveer een maand ago | 0

Answered
Large system of equations, vpaSolve returning empty sym
one approximate solution calculated by another software called "1stOpt": aliq: 2.78633151012791E-7 bliq: 25.4564536830427 ava...

ongeveer een maand ago | 0

Answered
problem solving nonlinear equation system with fsolve
here are solutions: x1: 1.80929329243556 x2: 1.67586180846898 x3: 1.19942316545143

ongeveer een maand ago | 0

Answered
Non linear system of equations
multi-solutions: 1: x1 0.00357502545408908 x2 1.88403841412371 x3 3.32997281546349E-5 x4 2.49981876993596E-6 x5 2.40013395...

ongeveer een maand ago | 1

Answered
Fsolve Error! Need help- Using Fsolve to solve system of non-linear equations.
Hi, your equations seems to be Contradictory: "nc*(t1-t2)-(t1-x5)" lead to x5=381.7598 while "x5-(2.5^(.28571429)*t1)" lead t...

ongeveer een maand ago | 0

Answered
How to solve a non-linear equation system as function handle with fsolve?
Multi-results: 1: q1: 2.96669036114669 q2: 1.70487333682449 q3: 15.5136953998108 q4: 5.27144773940526 q5: 0.14218964199662...

ongeveer een maand ago | 0

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