Alex Sha
Contribute at least one answer each month for 12 consecutive months
Awarded to Alex Sha on 03 Apr 2020
Answer 10 questions that were unanswered for more than 30 days
Awarded to Alex Sha on 09 Jan 2020
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Awarded to Alex Sha on 18 Sep 2019
Provide your first answer ever to someone else's question
Awarded to Alex Sha on 22 Apr 2019
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curve fitting a custom equation
Hi, all, as mentioned by Walter Roberson, the resule I provided above is obtained by using 1stOpt, the biggest advantage, for 1s...
curve fitting a custom equation
Hi, all, as mentioned by Walter Roberson, the resule I provided above is obtained by using 1stOpt, the biggest advantage, for 1s...
11일 전 | 0
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I want to solve 2 equations with 2 variables but it cant be solved and the command window shows fsolve stopped because the last step was ineffective
Hi, the result below should be one solution x1: -52.5485799573576 x2: 12.1032014174617
I want to solve 2 equations with 2 variables but it cant be solved and the command window shows fsolve stopped because the last step was ineffective
Hi, the result below should be one solution x1: -52.5485799573576 x2: 12.1032014174617
25일 전 | 0
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How to solve a system of second order nonlinear differential equations with boundary conditions
Hi, the chart will be given automatically in 1stOpt UI, also you can make chart yourself by using the result data given above. 1...
How to solve a system of second order nonlinear differential equations with boundary conditions
Hi, the chart will be given automatically in 1stOpt UI, also you can make chart yourself by using the result data given above. 1...
약 1달 전 | 0
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I need to fits the attached data as in image
Hi, the fitting function "y = p1/(1+Exp(p2+p3*x)+p4*x)^p5" is pretty good for all data set, where y=L, x=T 1: T1-L1: Root of ...
I need to fits the attached data as in image
Hi, the fitting function "y = p1/(1+Exp(p2+p3*x)+p4*x)^p5" is pretty good for all data set, where y=L, x=T 1: T1-L1: Root of ...
약 2달 전 | 1
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Objective function is returning undefined values at initial point. lsqcurvefit cannot continue.
The best results are as below, hard to be obtained since the initial-start values are impossible to be guessed reasonally. Root...
Objective function is returning undefined values at initial point. lsqcurvefit cannot continue.
The best results are as below, hard to be obtained since the initial-start values are impossible to be guessed reasonally. Root...
2달 전 | 0
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Kinetic parameter estimation and initial time setting
Hi, see the results below: Root of Mean Square Error (RMSE): 4.00513564326846 Sum of Squared Residual: 320.822230419589 Corre...
Kinetic parameter estimation and initial time setting
Hi, see the results below: Root of Mean Square Error (RMSE): 4.00513564326846 Sum of Squared Residual: 320.822230419589 Corre...
2달 전 | 0
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How to include contratins on 1 variables for this nonlinear system of equations?
Hi, refer to the solutions below: 1: x1: 0.415757622422666 x2: 0.321911265108838 x3: 0.0970690621849188 2: x1: 12.98212823...
How to include contratins on 1 variables for this nonlinear system of equations?
Hi, refer to the solutions below: 1: x1: 0.415757622422666 x2: 0.321911265108838 x3: 0.0970690621849188 2: x1: 12.98212823...
4달 전 | 0
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Fit points and specify the slope at one of the points
Hi, try the function below: y = p1+p2*x^2-p3*exp(p4*x); to ensure the slope being 0 in point of "x=0.985035", should add a con...
Fit points and specify the slope at one of the points
Hi, try the function below: y = p1+p2*x^2-p3*exp(p4*x); to ensure the slope being 0 in point of "x=0.985035", should add a con...
6달 전 | 0
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solving set of non linear equation
Hi, refer to the results below: phi1: 0.00687835881390378 phi2: 3.07608732711163
solving set of non linear equation
Hi, refer to the results below: phi1: 0.00687835881390378 phi2: 3.07608732711163
6달 전 | 0
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Trouble finding solution of unknown variable in difficult integration problem
Hi, there are two solutions as below: 1: h=0.073660616949704 2: h=0.165217787421255
Trouble finding solution of unknown variable in difficult integration problem
Hi, there are two solutions as below: 1: h=0.073660616949704 2: h=0.165217787421255
6달 전 | 0
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fsolve is not returning the right solutions
Hi, if you think the solutions should be (1,0,1) or (-1,0,1) , then one equation: F(3) = 1 + 2*x2.^2 + x3.^2; should be: F(3)...
fsolve is not returning the right solutions
Hi, if you think the solutions should be (1,0,1) or (-1,0,1) , then one equation: F(3) = 1 + 2*x2.^2 + x3.^2; should be: F(3)...
7달 전 | 0
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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...
9달 전 | 0
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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.
10달 전 | 0
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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...
10달 전 | 0
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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...
11달 전 | 0
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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.
11달 전 | 0
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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
약 1년 전 | 0
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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
약 1년 전 | 0
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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...
약 1년 전 | 1
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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...
약 1년 전 | 3
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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...
약 1년 전 | 1
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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.
1년 이상 전 | 0
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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...
1년 이상 전 | 0
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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...
1년 이상 전 | 0
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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 ...
1년 이상 전 | 1
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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...
1년 이상 전 | 0
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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
1년 이상 전 | 0
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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...
1년 이상 전 | 0
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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...
1년 이상 전 | 0
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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...
1년 이상 전 | 0
