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Solving a system of 5 dependent non-linear equations
My pleasure, it is actually very challenging problem, hard to be solved by common software or algorithms.

environ 6 ans il y a | 0

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fsolve & linsqnonlin cant solve my equations
The unique stable results: x1: 0.231780000872077 x2: 0.040000000119062 x3: 0.508699999227432 x4: 0.00060000005989538 x5: 4....

environ 6 ans il y a | 0

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Solving a system of 5 dependent non-linear equations
Hi, if vt = 0.0257, the solution should be: m: 512.891368076595 rsh: -1.08505661410065 rs: 3.40678689852078 io: 0.8568128664...

environ 6 ans il y a | 0

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Solving a system of nonlinear equations with bounded variables
There are two solutions: 1: q_b: 0.305291000916417 q_v: 0.0179815487538954 q_lp: 0.237309452162523 y: 1.25168611470519 pr:...

environ 6 ans il y a | 0

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Curve fitting with constraints
Hellow, Paul, if adding one more parameter in your fitting function, i.e. y = a*exp(b*x) + c*exp(d*x)+f Then: from y(0) = 0, w...

environ 6 ans il y a | 1

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how to solve a system of non linear-equations
Hi, I get the solutions below: 1: r1: 0.0136978624480164 r2: -0.0529268624480211 c1: 23794.5028958407 c2: 1043438.64860562 ...

environ 6 ans il y a | 0

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No solution found when solving 3 non linear equations
Hi, all, how about the solutions below, from the numerical perspective： 1： x1: -5.21219473201765E21 x2: -0.279500437676178 x...

environ 6 ans il y a | 0

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Multiple equations solving in MATLAB
Hi, Golam, post out your problem, we may try.

environ 6 ans il y a | 1

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8 nonlinear equations, 8 unknowns - little luck with fsolve/vpasolve
Hi, Alex Tekin, you may try some solvers or software package with the ability of global optimization, i.e. Baron, Lingo, 1stOpt....

environ 6 ans il y a | 1

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Non-linear Multivariate regression using genetic algorithm
The GA toolbox in Matlab is not an ideal tool for curve fitting with the goal of global optimizatiom result. Refer the result be...

environ 6 ans il y a | 0

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fminsearch for fitting a function to experimental data
There seem to be two sets of solutions: 1: Root of Mean Square Error (RMSE): 2.45406561689894 Sum of Squared Residual: 78.291...

environ 6 ans il y a | 0

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What is "Equation solved,fslove stalled'?
There are two solutions: 1: x1: -0.000499999999999997 x2: -2.28184863820141E-18 2: x1: -2.52247055758755E-18 x2: -0.000429...

environ 6 ans il y a | 0

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How can I find a correct value of the guess for my system of non linear equations ??
it is not easy to get correct initial start values, try to use global optimization algorithm instead of local ones like fsolve, ...

environ 6 ans il y a | 0

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Constrained Global Optimization Problem with MultiStart, GA and HybridFunction using Parallel Processing
the best results: Root of Mean Square Error (RMSE): 69.3464929074478 Sum of Squared Residual: 577072.329427525 Correlation Co...

environ 6 ans il y a | 0

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Failure in initial objective function evaluation. LSQCURVEFIT cannot continue.
Hi，Thaer Ismail， which is your exact fit function: "ydata=1-x1*exp(-(x2/xdata)^x3)" or "ydata=1-x1*exp((-x2/xdata)^x3)" ? if th...

environ 6 ans il y a | 0

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Least Square Curve Fitting, finding the initial start values in lsqcurvefit function in Matlab
if " the second and third number are 0.2 and 0.4.", then the result will be much better: Root of Mean Square Error (RMSE): 0.01...

environ 6 ans il y a | 0

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System of nonlinear equations
Hi，Mahboubeh， the results of your second case are much different with that of your first one, so in second case you use approxim...

environ 6 ans il y a | 0

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How can i calculate five unknown parameters??
There are multi-solutions for Charalampos's problem: 1: iph: -12.4464463252524 io: -889977.402184639 n: -4891.45375599277 ...

environ 6 ans il y a | 0

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I want to solve this equation. please help me
Here is the right solution, obtained from 1stOpt: a: -2.38880243947768E-9 b: 0.357245116257183 c: -32.3471147348507 d: -0.0...

plus de 6 ans il y a | 1

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Please help me to solve following equations using matlab
change the type of last three equations from (by removing denominator): 6.2975e-11 - (((x(6)^4)*(x(8)^8))/((x(4))*(x(5)^3)*(x(1...

plus de 6 ans il y a | 0

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Fslove don't find the right solution
I get the results: 1: q1: 31.25152 q2: -3.3648581278838E-15 q3: -37.1015437789933 2: q1: 31.2515200000001 q2: 1.378921962...

plus de 6 ans il y a | 0

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How to solve a nonlinear system of n equations
some results: 1: x1: 1.04727193704753 x2: 2.09481403258296 x3: -3.14176920919256 2: x1: -1.04719783053703 x2: 4.763975200...

plus de 6 ans il y a | 0

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Problem in using fsolve
Two of solutions: 1: x1 0.0302626794484622 x2 2.44987629792448 x3 -3.17840769482201 x4 -0.0245615818144686 x5 -0.291871074...

plus de 6 ans il y a | 0

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I have two equations that are difficult to solve, so I am using fsolve to get the sol. But while running the program I encountered the error .Please help me or tell other way to solve these equations.
there are two solutions: 1: F1: 0.458069398988435 f1: -1.13829069933547 2: F1: 0.280093672719386 f1: 0.0244403974479464

plus de 6 ans il y a | 0

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Why I cannot get a solution for this system?
A set of approximate solutions： lfd: 0.273760301072663 r1d: 0.0994325019367128 l1d: 0.236671205261253 l1q: 0.077183609924249...

plus de 6 ans il y a | 0

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i have system of 15 equations and 15 unknown when i use (vpasolve) after 45 minit i have solutions with Warning: Solutions might be lost. [solvelib::allvalues_warning]
Hi, it is easy to get the results below: y1: 4.99999995833333E-5 y2: 0.000199999986666668 y3: 0.0199999966666674 y4: 0.99999...

plus de 6 ans il y a | 0

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vpasolve: numeric instability when solving a system of three quadratic equations
The unique stable results are: u: 0.241646208739371 v: -1.29626943837113 w: 2.05462322963176

plus de 6 ans il y a | 0

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Fitting Data to a Non-Linear Curve
If don't care the function type, the follow is one: y = p1*(p2^x)*(x+p3)^p4; Root of Mean Square Error (RMSE): 0.0032240913289...

plus de 6 ans il y a | 0

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Curve Fit data using FIT
the fit function "myEqn='(-a/(1+exp(c*((x-b)/h).^2)-1))+d'" is not correct, refer to: the function should be: myEqn='(-a/(1+e...

plus de 6 ans il y a | 0

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Problem with fsolve: system of 6 nonlinear equations and more
a stable results: thot_membrane 470.276797155953 tcold_membrane 470.271756744994 thot_out -727.941719280904 thot_coolingplat...

plus de 6 ans il y a | 1