Answered

Solving lengthy nonlinear complex equations in complex variables

Try to find numerical solutions as below; y1s.realpart: 11.0169967890388 y1s.imagpart: -125.141575853451 y3s.realpart: 7.8197...

Solving lengthy nonlinear complex equations in complex variables

Try to find numerical solutions as below; y1s.realpart: 11.0169967890388 y1s.imagpart: -125.141575853451 y3s.realpart: 7.8197...

1 month ago | 0

Answered

Lsqnonlin_Fitting Data

Hi, if possible, please post out your data of each curve, as well as the fitting equation.

Lsqnonlin_Fitting Data

Hi, if possible, please post out your data of each curve, as well as the fitting equation.

2 months ago | 0

Answered

How to Fit a line to scatter data on scatter plot?

Hi, Chetan, if you don't mind the length of the fitting equation, refer to follow: x1=Speed, x2=Dp, y=Eff y = b0+b1*x1+b2*x1^2...

How to Fit a line to scatter data on scatter plot?

Hi, Chetan, if you don't mind the length of the fitting equation, refer to follow: x1=Speed, x2=Dp, y=Eff y = b0+b1*x1+b2*x1^2...

3 months ago | 0

Answered

Fitting a Custom Sigmoid

Hi，if the fitting function is： 1：y=a1*exp(-a2*exp(x)) Root of Mean Square Error (RMSE): 0.291990919479646 Sum of Squared Resi...

Fitting a Custom Sigmoid

Hi，if the fitting function is： 1：y=a1*exp(-a2*exp(x)) Root of Mean Square Error (RMSE): 0.291990919479646 Sum of Squared Resi...

3 months ago | 0

| accepted

Answered

Options when drawing using the Curve Fitting tool

Hi, post your data and function in txt format, if possible.

Options when drawing using the Curve Fitting tool

Hi, post your data and function in txt format, if possible.

3 months ago | 0

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Answered

How could I do simutanoues parameter fitting for two series experimental data and multiple datasets?

Hi, post your data please, if possible

How could I do simutanoues parameter fitting for two series experimental data and multiple datasets?

Hi, post your data please, if possible

6 months ago | 0

Answered

Using vpasolve to iterate/solve for flowrate in a piping network

refer to the result below: f1: 0.013713131883721 v1: 1.36937309476078 re1: 409175.227518161

Using vpasolve to iterate/solve for flowrate in a piping network

refer to the result below: f1: 0.013713131883721 v1: 1.36937309476078 re1: 409175.227518161

7 months ago | 0

Answered

Solving set of 5 non-linear simultaneous equations using fsolve

Hi, Anahita, if you don't want complex answers, then there are problems in your eauqtions, here taking second equation as an exa...

Solving set of 5 non-linear simultaneous equations using fsolve

Hi, Anahita, if you don't want complex answers, then there are problems in your eauqtions, here taking second equation as an exa...

7 months ago | 1

| accepted

Answered

Deconvolution of Guassian curve

Hi, you may try 4 Gauss Function: The results will be: Root of Mean Square Error (RMSE): 451.21462729511 Sum of Squared Res...

Deconvolution of Guassian curve

Hi, you may try 4 Gauss Function: The results will be: Root of Mean Square Error (RMSE): 451.21462729511 Sum of Squared Res...

7 months ago | 3

Answered

curve fitting toolbox for y=y0.exp((x0/x)^v) where data is known, but y0,x0 and v are unknown constants

Hi, Em, if fit as the function: y=y0.exp((x0/x)^v), then the result will be about： Root of Mean Square Error (RMSE): 9.39279339...

curve fitting toolbox for y=y0.exp((x0/x)^v) where data is known, but y0,x0 and v are unknown constants

Hi, Em, if fit as the function: y=y0.exp((x0/x)^v), then the result will be about： Root of Mean Square Error (RMSE): 9.39279339...

7 months ago | 1

Answered

Nonlinear regression with two variables

Hi, Dipon, post your y, T and pH data please, if possible.

Nonlinear regression with two variables

Hi, Dipon, post your y, T and pH data please, if possible.

8 months ago | 0

Answered

How can I solve this system of equation

Hi, VinceUgo, the eqn8 and eqn9 can be combined into one equation, so your problem become a system equation solving with eight e...

How can I solve this system of equation

Hi, VinceUgo, the eqn8 and eqn9 can be combined into one equation, so your problem become a system equation solving with eight e...

8 months ago | 0

Answered

Fitting data to an equation with complex part

lsqcurvefit is seneitive to initial start-values since it use local optimization algorithm, same as cftool, there is a GA toolbo...

Fitting data to an equation with complex part

lsqcurvefit is seneitive to initial start-values since it use local optimization algorithm, same as cftool, there is a GA toolbo...

8 months ago | 0

| accepted

Answered

Failure in initial objective function evaluation. FSOLVE cannot continue

You have three equations with three unknown parametrs, but initial start-values, you provide two only (x0=[1 1];), is this your ...

Failure in initial objective function evaluation. FSOLVE cannot continue

You have three equations with three unknown parametrs, but initial start-values, you provide two only (x0=[1 1];), is this your ...

8 months ago | 1

Answered

i need to solve 7 nonlinear equations with 7 unknows

refer the results below: Constant G x2 x1 x4 x3 x5 x6 x7 600 301.524350251906 299.992603098721 301.890052790606 305.9220213239...

i need to solve 7 nonlinear equations with 7 unknows

refer the results below: Constant G x2 x1 x4 x3 x5 x6 x7 600 301.524350251906 299.992603098721 301.890052790606 305.9220213239...

8 months ago | 0

Answered

Problems fitting couple differential equations to experimental data

Hi, if possible, upload your data (t, P and M) please

Problems fitting couple differential equations to experimental data

Hi, if possible, upload your data (t, P and M) please

8 months ago | 0

Answered

How to improve accuracy in fsolve?

There are multi-solutions with high enough accurancy, even given the range limition in [0, pi/2]: 1: a1: 0.996298496311242 a2...

How to improve accuracy in fsolve?

There are multi-solutions with high enough accurancy, even given the range limition in [0, pi/2]: 1: a1: 0.996298496311242 a2...

8 months ago | 0

Answered

Create a model to solve an energy balance

Hi, I get two solutions: No. 1 2 tg -328.861557610457 -549.471818197512 tm 1.72830356360143 -541.712011528394 hrpg -0.007275...

Create a model to solve an energy balance

Hi, I get two solutions: No. 1 2 tg -328.861557610457 -549.471818197512 tm 1.72830356360143 -541.712011528394 hrpg -0.007275...

8 months ago | 0

Answered

Fitting a profile to a Guassian Model

Hi, would you please upload your data file (dependent: alpha, independent variables: Temperature T, Pressure P, mass flow rate m...

Fitting a profile to a Guassian Model

Hi, would you please upload your data file (dependent: alpha, independent variables: Temperature T, Pressure P, mass flow rate m...

8 months ago | 0

Answered

How to fit complicated function with 3 fitting parameters using Least square regression

Hi, you may try to use "lsqcurvefit" command or curve fitting tool box (cftool), it is also better if you post data as well as k...

How to fit complicated function with 3 fitting parameters using Least square regression

Hi, you may try to use "lsqcurvefit" command or curve fitting tool box (cftool), it is also better if you post data as well as k...

8 months ago | 0

| accepted

Answered

Why is this not working

There are another five more solutions: No. x1 x2 x3 x4 x5 x6 x7 x8 x9 1 300 200 200 0 0.0447213595499958 -0.0447213595499958 3...

Why is this not working

There are another five more solutions: No. x1 x2 x3 x4 x5 x6 x7 x8 x9 1 300 200 200 0 0.0447213595499958 -0.0447213595499958 3...

9 months ago | 0

Answered

Fsolve complex results make no sense

Hi, Frederic Kluser, with your second case of Eq(9), I get the results below, all seem to be prefect: p: 1.79143003389998 p1_h...

Fsolve complex results make no sense

Hi, Frederic Kluser, with your second case of Eq(9), I get the results below, all seem to be prefect: p: 1.79143003389998 p1_h...

9 months ago | 0

Answered

Optimization of 9 unknown with 9 nonlinear constraints by fmincom

one inequality constraint is: x(1)-x(2)+x(3)-x(4)+x(5)-x(6)+x(7)-x(8)+x(9)<=0 (1) while one of equality constraint is: J*(x...

Optimization of 9 unknown with 9 nonlinear constraints by fmincom

one inequality constraint is: x(1)-x(2)+x(3)-x(4)+x(5)-x(6)+x(7)-x(8)+x(9)<=0 (1) while one of equality constraint is: J*(x...

9 months ago | 1

Answered

I am solving 20 nonlinear equation using fsolve to find 20 variables' value. But i previously know one of variable's value. That variable is x(17) in eqn F(17). x(17)=1200. Based on this fixed variable i want to find remaining variables' value.

The equation F(17) seems to be meanless: F(17)= (100e6*((0.5*(x(5)*x(6)+x(7)*x(8)))+(0.5*(x(11)*x(15)+x(12)*x(16))))/(-C*x(17))...

I am solving 20 nonlinear equation using fsolve to find 20 variables' value. But i previously know one of variable's value. That variable is x(17) in eqn F(17). x(17)=1200. Based on this fixed variable i want to find remaining variables' value.

The equation F(17) seems to be meanless: F(17)= (100e6*((0.5*(x(5)*x(6)+x(7)*x(8)))+(0.5*(x(11)*x(15)+x(12)*x(16))))/(-C*x(17))...

9 months ago | 0

Answered

How to guess initialization parameters for non-linear curve fitting with nlinfit?

Hi, Aindrila, guessing the initial start value is always a difficult task since the local optimization algorithms are adopted in...

How to guess initialization parameters for non-linear curve fitting with nlinfit?

Hi, Aindrila, guessing the initial start value is always a difficult task since the local optimization algorithms are adopted in...

9 months ago | 0

| accepted

Answered

using least square fit to find the best fit parameters

Hi， Annie， upload your data file please, if possible.

using least square fit to find the best fit parameters

Hi， Annie， upload your data file please, if possible.

9 months ago | 0

Answered

How to solve 3 non-linear equations with 3 unknowns?

One of numerical solution looks like: x: 4.49127153145489E-101 y: 0.0437692354838294 z: 867273686630772

How to solve 3 non-linear equations with 3 unknowns?

One of numerical solution looks like: x: 4.49127153145489E-101 y: 0.0437692354838294 z: 867273686630772

9 months ago | 0

Answered

How can I fit this data?

Hi, toon, how about the model function below: z = (p1+p2*x+p3*x^2+p4*y+p5*y^2)/(1+p6*x+p7*x^2+p8*x^3+p9*y+p10*y^2); where x: s...

How can I fit this data?

Hi, toon, how about the model function below: z = (p1+p2*x+p3*x^2+p4*y+p5*y^2)/(1+p6*x+p7*x^2+p8*x^3+p9*y+p10*y^2); where x: s...

9 months ago | 0

Answered

How do I find the coefficients of a function for a curve fit?

The below should be the best solution: Root of Mean Square Error (RMSE): 0.0255893453091926 Sum of Squared Residual: 0.0471466...

How do I find the coefficients of a function for a curve fit?

The below should be the best solution: Root of Mean Square Error (RMSE): 0.0255893453091926 Sum of Squared Residual: 0.0471466...

9 months ago | 0

Answered

Matlab curve fitting two equations simultaneously with common arguments

Hi, Liu, your fitting functions are overdeterminted, there are multi-solutions: 1: Root of Mean Square Error (RMSE): 0.1634941...

Matlab curve fitting two equations simultaneously with common arguments

Hi, Liu, your fitting functions are overdeterminted, there are multi-solutions: 1: Root of Mean Square Error (RMSE): 0.1634941...

10 months ago | 0