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Problem with fitting a loglog plot
polyfit doesn't like the log of zero. One option is to remove the first row of the data: data_exp_high = load("data_Q_1e-8.txt...

6 meses hace | 0

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Index in position 2 exceeds array bounds (Index must not exceed 1) errors?
N0 is a 4x1 vector, but you call it with two indices in the for loop! Turn N(1,j) into N(1) and similarly for the other calls t...

6 meses hace | 0

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How do I solve this ODE system where there exists derivatives in both sides?
You can separate the terms as follows:

7 meses hace | 0

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why am i getting grey figure box can someone fix please
Making some assumptions about your function pendulumODE, I think the following is more like what you expect to see: % Constants...

7 meses hace | 0

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Algae growing, concentration curve problem
Increase nt to 10000 and it works just fine for T = 20000.

7 meses hace | 0

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Error ''Array indices must be positive integers or logical values.'' when putting interval of 0.01 in a for loop
More like this: k = 0:0.1:2; n = numel(k); for i = 1:n x(i) = k(i); y(i) = k(i)*k(i) + 3*k(i) - 4; end plot(x,y...

7 meses hace | 0

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Trying to code from Polymath
Like this for example (I'll leave you to extract the numerical values): Wspan = [0 2]; % Integration range % Initial valu...

7 meses hace | 0

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Unable to solve differential equation with finite difference method
Should be more like this I think: b = 0.02; m = 80; L = 0.7; g = 9.81; J = m * L^2/3; a = 0; bet = 2; alpha = 0; beta = 3...

7 meses hace | 0

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FDM using succsesive overrelaxation method,
For w1 and T1 you have w1(:,Nx1+1) = (((la*B1*dx1)/(dx2*A1))*(w2(:,2)-w2(:,1)))+w1(:,Nx1); %Continuity of shear stress ...

7 meses hace | 0

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Solving first order ODE with initial conditions and symbolic function
You can do it numerically as follows: % input parameters Tinf=70+273.15; Ti=20+273.15; d=15e-2; r=d/2; cdepth=10/1100; Tf...

8 meses hace | 0

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can someone help me to analyze this program? How does the flowchart look like?
Perhaps this will help: %radiasi benda hitam % constants h=6.626e-34; c=3e8; k=1.38066e-23; % range of values lambda ...

8 meses hace | 0

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Error using surf (line 71) Data dimensions must agree
More like this? for it=1:2 for jt=1:3 zt(it,jt)=it+(jt-1); end end [x,y] = meshgrid(1:3,1:2); figure; surf(x...

8 meses hace | 1

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How to find Basins of attraction for the Halley method?
Don'tforget the dot multiply: f = @(z) z.^3 +1; df = @(z) 3*z.^2; ddf=@(z) 6*z; % its roots r1 = -1; r2 = 1/2 + 1i*...

9 meses hace | 0

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"Invalid use of operator." doesn't go even after trying various solutions :(
Why nor just use Matlab's inbuilt cart2pol function?

9 meses hace | 0

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Heat equation using Boundary condition
function statements of this form (i.e. functions eq1, initial and ba) need to go at the end of the script, not the start.

10 meses hace | 0

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A for loop that will run until a specific mathematical value is found
You could try replacing the "for i = 2:10 " loop by something like nports = 1; while Q(i)<Qdesired nports = nports ...

10 meses hace | 0

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How do I use an "if" statement to determine the highest input value?
Try help if

10 meses hace | 0

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How to plot all figures in only one plot?
Here's one simple way: x=-pi:0.1:pi; c=-6:5; figure hold on for i=1:length(c) y=c(i)*x.^(2)+4*x+2; plot(x,y) end...

11 meses hace | 0

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Error in Hermite Polynomial
In line for j = 0:i-1 you have j starting at zero. Matlab's indices start at 1, so the following line should have X(j+1) not ...

11 meses hace | 0

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Matlab code not computing
The use of square brackets in the scatter function is not the only problem! Are you looking for something like this? p=-1; z=...

alrededor de 1 año hace | 0

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how to plot the path of circular beam oscillation welding?
Like this? A=1; f=50; vf=0.02; time = linspace(0,100,500); x0 = vf*time; theta = 2*pi*f*time; x=A*cos(theta)+x0; y=A*sin...

alrededor de 1 año hace | 0

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how to change the direction of the airfoil
Change contourf(real(J),imag(J),imag(f),v2); %%%%% fill(real(zair),imag(zair),'k') to contourf(-real(J),imag(J),imag(f),v2);...

alrededor de 1 año hace | 0

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How to use 5 function coupled each other using ODE45? it is possible?
Better like this: MM0 = [10, 0, 0, 0, 0]; tspan = [0 100]; [t, MM] = ode15s(@mymode, tspan,MM0); M1 = MM(:,1); M2 = MM(:...

alrededor de 1 año hace | 0

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convert a column matrix with many rows into multiple column of equal rows
Try the reshape function.

alrededor de 1 año hace | 0

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"Not enough Imput arguments" ERROR
You haven't included J as an input argument to function Feedback_Ven_STEP.

alrededor de 1 año hace | 0

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Using polyfit in two arrays to detrend data.
polyfit just returns the coefficients of the polynomial. You need to use them in polyval to calculate data values.

alrededor de 1 año hace | 2

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Implicit solution using pdepe 1D advection diffusion reaction equation
I think you've overcomplicated the situation! Should be more like the following (which you should check very carefully, as I di...

alrededor de 1 año hace | 0

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I want to plot the vector field on F=x i+ j
Do you mean like this? [x,y] = meshgrid(-3:.15:3,-3:.15:3); Fx = x; Fy = ones(size(y)); %%%%%%%%%%% figure; quiver(x,y,Fx,F...

alrededor de 1 año hace | 0

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i have two set of data for temperature measurements which vary depends on each other. the variation may be divided into three portions. how can we seperate these portions
Here's a possible way (assumes the data is already in the workspace): dT2 = gradient(T2); minval = min(dT2(Time<2.5)); ix = f...

alrededor de 1 año hace | 0

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How to surf very small values keeping the same ratio?
Multiply them all by 1e4.

alrededor de 1 año hace | 0