Answered

How to use Matlab to find a pressure in a temperature and density spreadsheet using the nearest density value.

%Generate artificial data t = linspace(10,30, 25); p = linspace(1, 20, 20); [T,P] = ndgrid(t,p); d = exp(-((T-20).^2+(P-10)....

How to use Matlab to find a pressure in a temperature and density spreadsheet using the nearest density value.

%Generate artificial data t = linspace(10,30, 25); p = linspace(1, 20, 20); [T,P] = ndgrid(t,p); d = exp(-((T-20).^2+(P-10)....

22 days ago | 0

Answered

Kolmogorov-Smirnov (KS) Test

From the documentation: h = kstest(x,Name,Value) returns a test decision for the one-sample Kolmogorov-Smirnov test with additi...

Kolmogorov-Smirnov (KS) Test

From the documentation: h = kstest(x,Name,Value) returns a test decision for the one-sample Kolmogorov-Smirnov test with additi...

22 days ago | 0

Answered

Solving the hub location problem

You set % Renewal of population population = offspring; and offspring has only size 1x100 instead of 1x186. Thu...

Solving the hub location problem

You set % Renewal of population population = offspring; and offspring has only size 1x100 instead of 1x186. Thu...

23 days ago | 1

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Answered

Why does the value of tolerance stop at n=2 (third value of the iteration) within the while loop?

Maybe you mean tol = 1e-7 instead of tol = exp(-7) ? However: It's correct that MATLAB quits the while-loop after three val...

Why does the value of tolerance stop at n=2 (third value of the iteration) within the while loop?

Maybe you mean tol = 1e-7 instead of tol = exp(-7) ? However: It's correct that MATLAB quits the while-loop after three val...

24 days ago | 1

Answered

Minimization linprog constraint no feasible solution

The last equality constraint says that you want 0*x1 + 0*x2 + 0*x3 + 0*x4 + 0*x5 + 0*x6 + 0*x7 + 0*x8 = 6.6, thus 0 = 6.6 ... ...

Minimization linprog constraint no feasible solution

The last equality constraint says that you want 0*x1 + 0*x2 + 0*x3 + 0*x4 + 0*x5 + 0*x6 + 0*x7 + 0*x8 = 6.6, thus 0 = 6.6 ... ...

25 days ago | 0

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Answered

4th order Runge Kutta Method Differential System

Note that COne and CTwo are given in muF - thus they should be prescribed as 1000e-6 in your code, I guess. COne = 1000e-6; C...

4th order Runge Kutta Method Differential System

Note that COne and CTwo are given in muF - thus they should be prescribed as 1000e-6 in your code, I guess. COne = 1000e-6; C...

25 days ago | 0

Answered

Error using odearguments Vector Length issue

s3 = s(3) s5 = s(5) instead of s3=(s) s5=s(4)

Error using odearguments Vector Length issue

s3 = s(3) s5 = s(5) instead of s3=(s) s5=s(4)

27 days ago | 0

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Answered

Newton Forward difference method

Three coding errors: % Confirmed case Sample data points (x, y) data = [ 1, 88; 2, 49; 3, 47; 4, 8; 5, 34; 6, 762; 7, 98; 8, ...

Newton Forward difference method

Three coding errors: % Confirmed case Sample data points (x, y) data = [ 1, 88; 2, 49; 3, 47; 4, 8; 5, 34; 6, 762; 7, 98; 8, ...

27 days ago | 0

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Answered

integral using "int" function

Your code to produce g1, g2 and g3 does not matter. You don't get analytic expressions for the antiderivatives of g1, g2 and g...

integral using "int" function

Your code to produce g1, g2 and g3 does not matter. You don't get analytic expressions for the antiderivatives of g1, g2 and g...

27 days ago | 0

Answered

Ode23 is not outputting solutions at the times I specified between t0 and tf in tspan=[t0, t1, t2..., tf]

If you use the "soln" structure as result, ode23 only respects start and end point from your tspan vector. After the integrator...

Ode23 is not outputting solutions at the times I specified between t0 and tf in tspan=[t0, t1, t2..., tf]

If you use the "soln" structure as result, ode23 only respects start and end point from your tspan vector. After the integrator...

28 days ago | 0

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Answered

f(x) = x^2/3(3-x^2)(x-4). How do I enter this function in MATLAB?

Replace c = solve(fx); by c = solve(fx*x^(1/3)==0,'Maxdegree',3);

f(x) = x^2/3(3-x^2)(x-4). How do I enter this function in MATLAB?

Replace c = solve(fx); by c = solve(fx*x^(1/3)==0,'Maxdegree',3);

28 days ago | 0

Answered

Problem with integration: there is a pole on a contour

In the usual sense, your integral does not exist. But you can compute its principal value: syms z syms t real f = (z^2+3*z+2...

Problem with integration: there is a pole on a contour

In the usual sense, your integral does not exist. But you can compute its principal value: syms z syms t real f = (z^2+3*z+2...

28 days ago | 2

Answered

Integral2 seems to substitute non-scalar values of variable into integrand. Why?

"integral2" usually calls the function to be integrated with matrices of the same size for t1 and t2 to make the necessary funct...

Integral2 seems to substitute non-scalar values of variable into integrand. Why?

"integral2" usually calls the function to be integrated with matrices of the same size for t1 and t2 to make the necessary funct...

29 days ago | 2

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Answered

error when using lsqnonlin to function containing fzero function

"K" is a vector because "fraction" is a vector. Thus the "y" you compute in "denaturationfun" is a vector. But "fzero" cannot so...

error when using lsqnonlin to function containing fzero function

"K" is a vector because "fraction" is a vector. Thus the "y" you compute in "denaturationfun" is a vector. But "fzero" cannot so...

29 days ago | 0

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Answered

I'm trying to solve jeffry hamel equation using RK4 but it's not giving output as expected.

s = 6; Kn = 0.1; U20 = -1; U2 = fsolve(@(U2)fun_shoot(U2,s,Kn),U20) [Y,Z] = fun_odes(U2,s); plot(Z(:,1),Y) xlabel('U') yl...

I'm trying to solve jeffry hamel equation using RK4 but it's not giving output as expected.

s = 6; Kn = 0.1; U20 = -1; U2 = fsolve(@(U2)fun_shoot(U2,s,Kn),U20) [Y,Z] = fun_odes(U2,s); plot(Z(:,1),Y) xlabel('U') yl...

29 days ago | 1

Answered

Generalised solution to a n-order system of equations

Here is my code, that provies a range of answers from a to b, inclusive. Besides that you shouldn't give the same names to the ...

Generalised solution to a n-order system of equations

Here is my code, that provies a range of answers from a to b, inclusive. Besides that you shouldn't give the same names to the ...

1 month ago | 0

Answered

Unconstrained minimisation problem with a complicated range

I'll formulate the problem for one property - a generalization to three properties is obvious. I'll assume that each of the 3*N...

Unconstrained minimisation problem with a complicated range

I'll formulate the problem for one property - a generalization to three properties is obvious. I'll assume that each of the 3*N...

1 month ago | 0

Answered

I'm trying to solve a 2nd order ode with ode45, but have no idea where to start.

After dividing your equation by t, you can just follow the example Solve Nonstiff Equation under https://uk.mathworks.com/hel...

I'm trying to solve a 2nd order ode with ode45, but have no idea where to start.

After dividing your equation by t, you can just follow the example Solve Nonstiff Equation under https://uk.mathworks.com/hel...

1 month ago | 0

Answered

How to solve for 1D non homogenous ODE by Finite element method

I usually set A(1,1) = 1, F(1) = 0, A(N+1,N+1) = 1, F(N+1) = 2 and only loop from 2 to N here: %%%% Assembling %%%% for i=1:...

How to solve for 1D non homogenous ODE by Finite element method

I usually set A(1,1) = 1, F(1) = 0, A(N+1,N+1) = 1, F(N+1) = 2 and only loop from 2 to N here: %%%% Assembling %%%% for i=1:...

1 month ago | 0

Answered

How do I change my scalars to fit my normpdf?

xq = 0:100; mu = [25, 50].'; sigma = [5, 10].'; ndist = 1./(sigma*sqrt(2*pi)).*exp(-((xq-mu)./sigma).^2); plot(xq,ndist) g...

How do I change my scalars to fit my normpdf?

xq = 0:100; mu = [25, 50].'; sigma = [5, 10].'; ndist = 1./(sigma*sqrt(2*pi)).*exp(-((xq-mu)./sigma).^2); plot(xq,ndist) g...

1 month ago | 1

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Answered

newton raphson for nonlinear heat equation scheme

Why don't you use "pdepe" ? Ten lines of code maximum, and you are done. To get rid of the error in the above code, replace % ...

newton raphson for nonlinear heat equation scheme

Why don't you use "pdepe" ? Ten lines of code maximum, and you are done. To get rid of the error in the above code, replace % ...

1 month ago | 0

Answered

How to quantify shape similarity between two vectors.

Shift the curves by their means first so that the means of all objects lie in the origin (0). This will remove translational dif...

How to quantify shape similarity between two vectors.

Shift the curves by their means first so that the means of all objects lie in the origin (0). This will remove translational dif...

1 month ago | 0

Answered

input appears to be a function and variable and exceeds the number of array elements???

You define a string of length 59 named "input". Then you want to use "input" as the MATLAB command to request user input for "ag...

input appears to be a function and variable and exceeds the number of array elements???

You define a string of length 59 named "input". Then you want to use "input" as the MATLAB command to request user input for "ag...

1 month ago | 0

Answered

How to solve for the maximum or minimum value of a symbolic function

syms Vr theta_r Vse rho gamma positive real syms X_r positive real syms n_t positive real syms Vs positive real syms x y l...

How to solve for the maximum or minimum value of a symbolic function

syms Vr theta_r Vse rho gamma positive real syms X_r positive real syms n_t positive real syms Vs positive real syms x y l...

1 month ago | 0

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Answered

An error 'matlabexecutionerror' occurred when i use 'min' in type optim.problemdef.OptimizationExpression

"min" is not a supported operation for optimization variables: https://uk.mathworks.com/help/optim/ug/supported-operations-on-o...

An error 'matlabexecutionerror' occurred when i use 'min' in type optim.problemdef.OptimizationExpression

"min" is not a supported operation for optimization variables: https://uk.mathworks.com/help/optim/ug/supported-operations-on-o...

1 month ago | 0

Answered

How do I make x the subject of this function?

D = 0.05; Y = 0.2170535; f = @(X) Y - (D^2 * acos(1-(2*X/D)) - sqrt(X.*(D-X) .* (D-2*X)) / (pi*D^2)); X = 0:0.001:0.025; plo...

How do I make x the subject of this function?

D = 0.05; Y = 0.2170535; f = @(X) Y - (D^2 * acos(1-(2*X/D)) - sqrt(X.*(D-X) .* (D-2*X)) / (pi*D^2)); X = 0:0.001:0.025; plo...

1 month ago | 0

Answered

Is there a function to create the P-P plot in Matlab, to compare two cumulative distribution functions against each other?

rng default; % for reproducibility a = 0; b = 100; nb = 50; % Create two log-normal distributed random datasets, "x" and "y...

Is there a function to create the P-P plot in Matlab, to compare two cumulative distribution functions against each other?

rng default; % for reproducibility a = 0; b = 100; nb = 50; % Create two log-normal distributed random datasets, "x" and "y...

1 month ago | 1

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Answered

give correction to my code for finding value of three variable by newton rapson iteration.

The residual for your initial guess is [191,44,534], the residual for the last column of Z is [75e-9,10e-9,9e-12]. Thus obviousl...

give correction to my code for finding value of three variable by newton rapson iteration.

The residual for your initial guess is [191,44,534], the residual for the last column of Z is [75e-9,10e-9,9e-12]. Thus obviousl...

1 month ago | 0

Answered

Adjacency matrix for ODE45

k = [0,0.1,0.2,0]; reshape(k,2,2) I think you want the reshaped matrix to be reshape(k,2,2).'

Adjacency matrix for ODE45

k = [0,0.1,0.2,0]; reshape(k,2,2) I think you want the reshaped matrix to be reshape(k,2,2).'

1 month ago | 0

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Answered

Numerical solution for the heat equation does not match the exact solution

I cannot believe that the value for alpha has no influence on the solution. So I guess that the exact solution maybe holds for...

Numerical solution for the heat equation does not match the exact solution

I cannot believe that the value for alpha has no influence on the solution. So I guess that the exact solution maybe holds for...

1 month ago | 2

| accepted