Answered
Plotting a function with 2 dependent variables
Use meshgrid instead: [x,y] = meshgrid(-10:0.1:10); z = sin(x).*cos(y); plot3(x,y,z)

4 years ago | 0

Answered
How to plot streamlines continuously?
Not entirely sure what you mean. Changing startx and starty values? In your code you set the starting values on the y-axis to 0....

4 years ago | 1

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Answered
ode45 solver SIR model
Hi Ollie, to get the area under the curve, just add another integration variable that integrates over the curve, y(2), I called...

4 years ago | 1

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Answered
Extracting specific parts of an array
Assuming your variable is called data_velocity use something like: extractdata = data_velocity(data_velocity<0.1 & data_velocit...

4 years ago | 0

Answered
Simple For cycle (a small problem with the indexes)
There you go: omega_vet(1) = 55000; for i=1:length(phi_10(init:end)) x_ER_vet(i) = interp1(mass_flow_turbine_cor...

4 years ago | 1

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Answered
How can I get the first zero maximum in my program?
Georges, you could use something like this to find your first zero: b(find((abs(a)<1e-12),1)) Of course, this is assuming, for...

4 years ago | 0

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Answered
Displaying actual values from coded values for a for loop.
Wiktor, simply replace the is_leap_year(i) command with an if statement. Quick and dirty: if (strcmp(is_leap_year(i),'True')) ...

4 years ago | 0

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Answered
question about fplot function
Hi Kris, syms y(x) Dy = diff(y,x,1); DDy = diff(y,x,2); ysol = dsolve(DDy + 3*Dy == 12*x - 5, y(0) == 1,Dy(0) == 0) fplo...

4 years ago | 0

Answered
Sorting array by datetimes does not work
Convert to and sort the table: T = sortrows(cell2table(HR_date_time_strings),2)

4 years ago | 0

Answered
Turning my function into an infinite loop
Hi Faris, instead of a for loop use a while loop with a condition like while abs(s_k - s_k1) > TolMax % here comes your co...

4 years ago | 0

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Answered
How long do I have access to Matlab on a Academic license?
Matthew, your academic license is good for one year starting from the date the license has been purchased. Contact me directly a...

4 years ago | 1

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Answered
How do I change axes scale in a surface plot by a predefined factor?
Iron, if it just about changing the labels simply use xticklabels(). See the example below: x = linspace(-10,10,200); y = cos(...

4 years ago | 0

Answered
Error when opening a new figure
Hi Ran, in the error message it says that 'figue' is not recognized. There may be an 'r' missing (to make it 'figure'). If this ...

4 years ago | 0

Answered
How to use unique in a conditional statement nested in for loop?
Usman, you could do it this way. First compute all solutions in a matrix X and then compute unique values. n = 1000; for a = 1...

4 years ago | 0

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Answered
Failure in initial objective function evaluation. FSOLVE cannot continue.
Ahmed, use the following: fhandle = @Sample13; options = optimset('display','off','Algorithm','levenberg-marquardt'); a ...

4 years ago | 0

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Answered
Hourly and 6-hourly average of data in timeable
Phoebe, it looks like your data points are all equally spaced(?), 10 minutes. Check out the movmean() command.

4 years ago | 0

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How to arrange correctly with a graph
Anton, add t as an input arg to: function y_out=rhs(t,y)

4 years ago | 1

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Answered
(FOR STEP RESPONSE GRAPHICS) how to make an inset of matlab figure inside the figure
Hi Dorukhan, add another axes() to the bottom of your code. E.g. p = get(gca, 'Position'); h = axes('Parent', gcf, 'Position'...

4 years ago | 0

Answered
Error in my ode45 equation.
Hi Zara, your vector of initial conditions has 5 components yo = [4 0 0 1 500.15]; however, you only have 4 differential equa...

4 years ago | 0

Answered
Error - matrix dimensions must agree
Hi Joe, I think this is what you are trying to do: x0 = 2; y0 = 2; x = [x0; y0]; iter = 0; max_iter = 100; tol = 0.001; ...

4 years ago | 0

Answered
Grid a plot with diagonal lines
There are a couple of things you could do. E.g. x = -5:1:5; N = numel(x); X = ones(N,1)*x; Y = X + X'; plot(X',Y'); grid

4 years ago | 0

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Answered
how to calculate the index of minimum value in each column cell array
Mohammad, use cell2mat() to convert the cell array to an ordinary array (e.g. A) and then use [val,loc] = min(A,[],1)

4 years ago | 1

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Answered
Graph can not show correct point
Hi Carey, ode45() picks its own time steps to do the integration. However, you can prescribe the times at which you want integra...

4 years ago | 0

Answered
how to plot to some maximum axis level?
Add axis([0 70 -inf inf])

4 years ago | 1

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Answered
Problem with plotting equation
Hi George, use fimplicit(): syms x y f(x,y) = log(y/x)-(sigma_e/sigma_a)*(log(1+x*sigma_a*tau*lambda_0/(h*c))-log(1+(x*sigma_a...

4 years ago | 0

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Answered
Error using symfun>validateArgNames (line 333) Second argument must be a scalar or vector of unique symbolic variables.
Hi Ahmed, almost there: syms x y y = symfun(x + exp(x),x); figure(1) fplot(y,[-13,13]) grid on In your code you declare x ...

4 years ago | 0

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Answered
how to get higher order derivative in ODE function
Hi Giacomo, when you solve the ODE this means you have solutions for y(t) and y'(t). You can then simply use the same equation f...

4 years ago | 0

Answered
How to solve "index exceeds the number of array elements"
Hi Ryan, try something like this: fl = 100; fu = 1500; % replace as necessary N = 100; f = linspace(fl,fu,N); cm = 0; f...

4 years ago | 1

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Answered
Fixing code to plot an ODE
Hi, you are almost there. This should get you started: hold on for n=1:200 p=.01*n; alpha=[.1; .5; .3]; beta=[....

4 years ago | 1

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Answered
Change value of variable in while loop
Hi Anon, based on your problem description and assuming you are simulating the motion of one projectile in 3D I suggest you use...

4 years ago | 0