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linear vs nonlinear regression model
@Mohammadreza As I said in my comment, there are two different kinds of linearity. Consider the model: y = a*exp(x) Is y line...

3 years ago | 2

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Answered
How to convert a string like "2.0:0.25:10.0" into a vector of floats?
A few ways I can think of immediately. S = "2.0:0.25:10.0" V = eval(S) V = str2num(S)

3 years ago | 1

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Answered
How do you go about guessing for fitting parameter initializations?
There is no magic way to guess parameter estimates for any nonlinear problem. Sorry, but true. And of course, if there was, then...

3 years ago | 0

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I try to find a general vector base for all magic squares of dimension n . Why does this program work for n = 3, but not vor n > 3?
No resonse yet? Again, I don't see why you are using rref here. If all you want are basis vectors, then tools like null and orth...

3 years ago | 1

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Answered
will there be support for version 2 of the twitter api?
In general, we cannot tell you IF there will be support for anything. The MathWorks does not release information about their pla...

3 years ago | 2

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how can I take elements of an array as input to a function in a set of 10 elements each?
A terribly confusing question. (Even if I ignore the fact that your subject says 10 elements, but the question text says 26 elem...

3 years ago | 0

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How can I create a spline with conditions on the middle?
Just use my SLM rtoolbox. It can impose literally any condition on a spline that you want. And it can impose conditions on the s...

3 years ago | 1

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Finding four input combinations with the same output value by interpolation method, and find the one that minimizes the cost function.
Um, your technique will not really solve the problem. It approximates the solution. Regardless, you will now have difficulties e...

3 years ago | 0

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Sum a matrix element using a window size of 4
Reshape the array, to be now of size 4x4x2 A = [-2 -2 -2 2 -2 2 -2 -2 -2 2 -2 -2 -2 -2 -2 2 -2 -2 2 -2 -2 2 2 2 ...

3 years ago | 0

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how to compute intersection of union for two polygons?
T1 = importdata('T1.mat'); T2 = importdata('T2.mat'); polygon1= [T1(:,1),T1(:,2)]; plot(T1(:,1),T1(:,2),'b.') hold on plot(...

3 years ago | 1

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Answered
fmindnd problem doesnt run
Never just say something does not run, and nothing more. Would you tell your doctor that something seems wrong, and hope they ca...

3 years ago | 0

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Suppose i have a matrix (2x4) A=[1 2 3 4;5 6 7 8] and i want to change it into this matrix [1 2;3 4;5 6;7 8]. How to do that?
help transpose help reshape Essentially, you need to learn how elements are stored in a matrix. You need to learn to manipulat...

3 years ago | 0

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how to fit a curve in matlab?
You really have very little signal, compared to what is apprently noise in those "curves". As such, you would be ill-advised to ...

3 years ago | 0

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How to change specific numbers to 0
For some reason? Learn to use ismember instead. What you think makes sense does not work in MATLAB. And that means you need to s...

3 years ago | 0

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Help with solve and symbolic equations
The first equation does not use i0 at all. So it makes no sense to try to solve two equations for one unknown anyway, where that...

3 years ago | 1

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Answered
bilinear extrapolation based on interp2
Ugh. This is just a bad idea, Extrapolation in general is a bad thing to do. A better word is probably excrapolation. You will g...

3 years ago | 1

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How to take the middle of a list?
"really specific" issues probably means that it makes no sense to ask for the middle 3 elements of a VECTOR (Python has lists, M...

3 years ago | 1

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Inverse input/output of switch case function
In general, no, that is not possible, at least to get MATLAB to do this automatically for you (if your mapping is not a single-v...

3 years ago | 2

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Answered
What resample method can I use for time series that increases nonlinearly?
This is really an interpolation problem. You can call it a resampling, but interpolation is all it is. And you can do everything...

3 years ago | 1

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Answered
Is there a way to constrain singular value decomposition results?
No. You cannot constrain the SVD (as employed by PINV, I assume) to yield a solution that obeys bound constraints. That computa...

3 years ago | 0

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Need gradual data values.
Actually, it IS quite a smooth curve. Almost perfectly smooth, in fact. y = [0.0320415867172945 0.184398415806668 0.0...

3 years ago | 0

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How to surf very small values keeping the same ratio?
I THINK what you are asking is how to make the surface show there is little variation in z. I'll make up an example... [X,Y] = ...

3 years ago | 0

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Answered
Subdividing a 2-D Polygonal Shape Using Values Given in an Array
Sadly, this is an impossible task to do perfectly. Even imperfectly is difficult. And wanting quadrilaterals makes it harder yet...

3 years ago | 0

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Answered
Will the MATLAB Answers community diminish/obsolete with the rise of AI-based chatbots?
Will it? Well, CAN it? Yes, of course. I have no claim to omniscience, nor any reservations that something or someone would/coul...

3 years ago | 2

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Answered
How do you get first n number of solutions while solving numerically ?
Too late, since you have an answer that solves your problem to your satisfaction. I want to point out something you probably nee...

3 years ago | 1

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How to solve the problem of convergence at the infeasible point？
You have 22 unknowns, and 18 constraints, 12 or them linear, but the other 6 are nonlinear equalities. A 22 dimensional space is...

3 years ago | 0

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gernerating standard normal variable in matlab
I'm a little confused. Why would you expect the result (of z*z') would be even remotely close to an identity matrix? In fact, yo...

3 years ago | 0

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Set Element Index to 1
Your real problem is you misunderstand what you are doing, in wanting to write a Newton-Raphson code! If I had to guess, your co...

3 years ago | 0

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Random numbers generation based on specific distribution function, then sort in specific way
Where is the problem? You don't say what the distribution of those numbers is, so absolutely nothing can be done until you deci...

3 years ago | 0

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constrain the csapi fitting to positive values
I'm sorry, biut you cannot constrain an interpolating spline built by csapi to be everywhere positive. The mathematics of how th...

3 years ago | 0

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