Answered
How to Solve matrix equations in Matlab
Your method seems valid. But of course fsolve will only attempt to find a local solution, and it might get stuck in a place wher...

1 year ago | 1

Answered
Index exceeds the number of array elements
The argument in brackets should be an index number, so for example: x = 1:10; %a 1 x 10 vector for ix = 1:size(x,2); f(ix) = ...

1 year ago | 0

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Answered
How to put fsolve in a loop, using 2 unknowns?
Replace the first line with: H = @(X)fsolve_root_finding(X(1),X(2));

2 years ago | 0

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Need to apply trapezoidal rule for double integration with an array by using the for loop
There are two things that need correction: 1) Remove the line i=i+1. This is what the for loop does. (also don't use "i" in ge...

2 years ago | 0

Answered
Error in find Precision recall curve
Try without the quotations: [XCrit,tpr,YCrit,ppv] = perfcurve(Y,diffscore1,'HandGrip'); In general quotations are used to sp...

2 years ago | 0

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Answered
I am solving a nonlinear Model predictive control problem . I get the following error. Can anybody help me understand the error report?
The error says that the derivative at the initial point (x0) is either NaN, infinity, or complex. So you should check whether th...

2 years ago | 0

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Answered
time series interpolation of irregular data
You can use "griddedInterpolant". I would use 'pchip' as method.

2 years ago | 0

Answered
Multiple sample values into scatteredInterpolant
What works is: Make a 3D array from B, so: for ih=1:length(B) B_3D(:,:,id) = B{ib) end And then add a vector 'h...

2 years ago | 0

Answered
x undefined (Catenary Cable Case Study)
What you have done is programmed a function. So this function calculates fval when you give a value of x. You can now call this...

2 years ago | 1

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Answered
Locating point on x-axis where the slope is decreasing
Bascially you want to get the index when the change in theta becomes negative: dtheta = diff(theta); index = find(dtheta<0,1...

2 years ago | 0

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Conversion to logical from sym is not possible.
g = 3; eff1=@(rr)-(1.8-0.8.*(1+rr)./(1-7.56.*g*rr))*rr/(0.01-0.11.*rr+0.06.*exp(23*rr)); x=fminbnd(eff1,-1,1); You could s...

2 years ago | 0

Answered
Hourly averages over a 20yr time series
Its not exactly clear over which values you want to calculate the mean, but have a look at this function, that can calculate mov...

2 years ago | 0

Answered
Removing/clearing NaN/0 values from matrix/array data
A1 = A(A~=0 & B~=0) should work

2 years ago | 0

Question

1 iteration in fsolve: new x and no more
I want to use fsolve to only use one iteration: get the Jacobian, get x1 and done. However when test the code below, which tries...

2 years ago | 2 answers | 0

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answers

Answered
Optimization of system ODE
It is still not clear what your problem is. Do you get an error? Do you get a different solution than you expected? Anyway f...

2 years ago | 1

Question

Why is EACH function evaluation inside a parfor loop much faster then ONE evaluation outside the loop?
Basically I calculate a finite difference Jacobian of a function, as shown below. The function evaluation labelled SINGLE RUN t...

2 years ago | 0 answers | 0

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Question

Second Order optimality fmincon
Someone explained the second order condition for optimality of a constrained optimization problem here: https://math.stackexch...

4 years ago | 0 answers | 0

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Question

Incorrect solution for symmetric problems in fmincon
If I maximize XX(1)^2+XX(2)^2 subject to x1 + x2 <=1 and use starting value X0=[0.5,0.5] I get as solution X=[0.5,0.5], although...

4 years ago | 1 answer | 0

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answer

Question

patternsearch with nonlinear equality constraint: any advice for more efficient steps?
Dear all, I have a constrained optimization problem which is not differentiable (because of some random errors), but it should ...

4 years ago | 0 answers | 0

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Answered
How to normalize curves with multiple peaks such that each peak will be 1 and each valley will be 0?
Yeah, you would have to calculate a scaling factor for each peak/trough. In one dimension you can then use the scaling factor fo...

4 years ago | 0

Answered
Tangent at a given point to a nonlinear curve
I think you need to be a bit more precise in what you want: you have data with errors in them, and you want to fit a curve that ...

4 years ago | 0

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Answered
Matlab R2014A blurry on high-dpi windows device
Two things did it for me: 1. go to matlab/bin and right click application, choose compatibility and check "disable scaling on h...

7 years ago | 0

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fmincon and exitflag = -2 or 2 / non respect of constrained conditions
getting exit message 2 is not bad but if you insist on having 1, you could try to use smaller values for TolX (ie.. 1e-10 or eve...

8 years ago | 0

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Answered
Why does the first value in loop get overwritten
Thanks guys... normally i never save iteration variables like 'fi' but in this case the files contained "fi = 1". very silly

10 years ago | 0

Question

Why does the first value in loop get overwritten
For some reason when fi == 1, NPV_list(1,1) is inserted correctly, but when fi=2 the value gets overwritten, which i dont unders...

10 years ago | 3 answers | 0

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Answered
Vectorize sum of discount rates
thank you all for you answers... all did what i wanted, but the one by Matt Fig is the most simple

10 years ago | 0

Question

Vectorize sum of discount rates
Hi, I want to vectorize the calculation of series like this: [R^0;R^0+R^1;R^0+R^1+R^2;...etc. Im quite sure this should b...

10 years ago | 4 answers | 0

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Answered
sum elements of matrix if...
It seems i can not edit my comment... so here again (sorry for mess, but i forgot to 'code' my code) Ok, i was not clear let ...

10 years ago | 0

Question

sum elements of matrix if...
Hi, lets say i have two matrices: A=rand(5,10); B=[ones(1,10);3*ones(1,10);ones(1,10);ones(1,10);3*ones(1,10)]; I...

10 years ago | 2 answers | 0

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Answered
fixed-point iteration for root finding
a while loop might be a good idea: err_lim = 1e-6; x_new = %initial guess err = err_lim *2; %arbitrary to pass while ...

11 years ago | 0