0
votes
1answer
48 views

MATLAB: Approximate tomorrow's temperature with 2nd, 3rd and 4th polynomial using the Least Squares method.

The following is Exercise 3 of a Numerical Analysis task I have to do as part of my university course on the subject. Find an approximation of tomorrow's temperature based on the last 23 values ...
0
votes
2answers
105 views

How do you generate a surface who's value around the origin is within some range

What's a quick way to generate a smooth, closed-form surface that will be within the range $[0,1]$ for $x, y \in [-1,1]\times[-1,1]$? The surfaces should be of similar complexity to $2\times2$-degree ...
0
votes
0answers
46 views

Finding the solution space computationally for a polynomial degree 4.

I've been working on a problem that has led me to an extremely long, degree 4, polynomial of the form: $$f=f(\vec{k})=f(k_1,k_2,k_3).$$ My objective is to describe the solution space in $\vec{k}$ for ...
0
votes
0answers
37 views

What are the coeff. of this polynomial?

My matlab generates this answer for the problem: p = -20.2090 17.3368 272.9057 -0.7528 Is it correct? It seems I've gotten different results in another ...
0
votes
2answers
115 views

Creating image in matlab with specified level sets of a complex polynomial.

I am trying to create an image in matlab which contains specified level sets for a complex polynomial. Suppose, for example, I wanted to create an image containing the sets ...
2
votes
2answers
622 views

Lagrange polynomial and derivative problem

I need to code this function in matlab $$L'(x) = \sum_{k = 0}^{n} f_k l_k(x) $$ Where's $l_k$ looks like this $$l_k(x) = \sum^{n}_{j=0, j \neq k} \frac{\prod^{n}_{i=0}(x - x_i)}{(x - ...
0
votes
1answer
52 views

Non linear curve

If there are set of points (16.26,1000) (8.814,2000) (6.06,3000) (4.602,4000) in a similar way if you plot these points in matlab you will get a nonlinear curve. After getting that curve, how to find ...
2
votes
1answer
297 views

Automatic calculation of the intersection of discrete curves

first of all, let me apologize for a poor math-english translation, I'll try my very best. I have the following situation: I have over 16.000 data files which I generated from a biometric ...
0
votes
2answers
151 views

How to validate this Matlab code?

I am new to Matlab, help please. In the book I saw this picture for the following polynomial: $$g(t)=x_1+x_2t+x_3t^2+ \ldots +x_{10}t^9$$ for some $t$ and $g(t)$. The following code is given: ...
0
votes
1answer
9k views

How to use polyfit() function in Matlab?

First of all i am new to Matlab, and not sure whether to use polyfit or something else for my problem. I plotted a graph with the following matlab code: ...
1
vote
1answer
146 views

Trying to sort the coefficients of the polynomial $(z-a)(z-b)(z-c)…(z-n)$ into a vector

So I have a factored polynomial of the form $(z-a)(z-b)(z-c)\ldots(z-n)$ for $n$ an even positive integer. Thus the coefficient of $z^k$ for $0 \le k < n$ will be the sum of all distinct $n-k$ ...
1
vote
1answer
246 views

Representation of Fourier Transform's vectors

I am just learning FFTs and I am trying to debug a problem in MATLAB. I think I don't understand how is MATLAB's FFT function handling the polynomial powers, or I am doing something wrong manually. ...
1
vote
3answers
988 views

Linear Algebra Question (Polynomial Interpolation)

Given the data for an experiment: Velocity: 0, 2, 4, 6, 8, 10 Force: 0 , 2.9, 14.8, 39.6, 74.3, 119 (One force value listed below one velocity value in a table) Find an interpolating ...