# How to fourier transform a gaussian curve?

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Antonio Sarusic on 26 Feb 2020
Hello,
I have the following function:
x_fit_func(x) = a1*exp(-((x-b1)/c1).^2);
a1, b1 and c1 are all constants and the function represents a gaussian curve.
Now I want to fourier transform this function and in theory i should again get a gaussian curve.
I tried it like this
x_F = fft(x_fit_func(x));
or like this
x_F = fft(x_fit_func);
But it always calculates something that is not a gaussian curve.
Does anyone know what I do wrong?
Thanks
Antonio

Star Strider on 26 Feb 2020
The ‘x_fit_fcn’ is not syntax that MATLAB recognises (except in the Symbolic Math Toolbox), as a function.
x_fit_func = @(x) a1*exp(-((x-b1)/c1).^2);
I also calculated the fft of the result tthat produced. It works.
Star Strider on 27 Feb 2020
As always, my pleasure!

DISHANTKUMAR PATEL on 1 Dec 2022
% isotropic Gaussian parameters n = 65; % resolution s = 2; % width x = linspace(-5,5,n); [X,Y] = meshgrid(x); gaus2d = exp( -(X.^2 + Y.^2 )/(2*s^2)); figure(1), clf surf(x,x,gaus2d) rotate3d on hold on % adjusting the radius of sphere x1 = x1*s; y1 = y1*s; z1 = z1; % add a constant to sphere, so that it is on top of gauss addi = max(gaus2d(:)) - min(z1(:)); z1 = z1 + addi; surf(x1,y1,z1) realCenter = [8,15,25]; [X,Y,Z] = sphere; XYZ = bsxfun(@plus,r*[X(:),Y(:),Z(:)], realCenter) % Label axes. xlabel('X', 'FontSize', 8); ylabel('Y', 'FontSize', 8); zlabel('Z', 'FontSize', 8); title('3D Sphere'); axis equal;