How to generate a function from x-y vectors?

Hello MATLAB users. I got two vectors (say x and y). Is there any way to create a function i.e. y=f(x). I do not want the expression. I just want to create the function in matlab for further calculations. For ease: x=[1 5 0 32 8]; y=[10 1 654 32 100];

[the cyclist]

Your question is not clear. What does "use these vectors in function form" mean?

Do you mean you want to find a function f(x) that will (approximately?) fit the x-y data? If so, what type of function? A polynomial?

[Ajay Goyal]

If I do not get expression; its ok. I just want to create a funtion from these vectors so that further calculations like Fourier series etc can be done

Answer 1

[Nicolas Schmit]

You question is not very clear, so I will try to guess what you are trying to do.

If you want to define a purely symbolic function f(x), use the following syntax.

syms f(x)

If you want to create a function from data points x and y, use the griddedInterpolant function to create a interpolation of x and y.

x=[1 5 0 32 8];
y=[10 1 654 32 100];
[~, index] = sort(x);
F = griddedInterpolant(x(index), y(index));

[Ajay Goyal]

Thank You, Nicolas Schmit

[Ghenam Dahmane]

Thank you for your help Nicolas Schmit

Answer 2

[Yifan Ma]

What you are looking for is map container. https://de.mathworks.com/help/matlab/ref/containers.map-class.html

Answer 3

[Luca]

Hi,

I have 2 vector (x, y) and I desire math expression y=f(x)

x must be syms. How to?

tnks

[Ajay Goyal]

Hi,

As much I did understood your query, you wish to establish relation as y=f(x) and values of x are not known. To answer, I believe, it is not possible as the values of x and y is the first necessity to develop a function. Then only you may use it to predict y for input values of x.

Contrary, if you just want to define a function, you may do it following way:

%%%%Main File:

syms x

[ y ] = Untitled2( x )

%%%%Function file:

function [ y ] = Untitled2( x ) %%%%same name as in main file. Func. file will be stored with this name

y=x.^2; %%%%wrtite the function. Say

end

Kindly let me know, if your query has been resolved.

Best Luck

Ajay

[Ajay Goyal]

both files has to be in the working folder

Answer 4

[Luca]

For you.