MATLAB: Cubic Spline Fit-Just confirm the code

cubicfitinterpolationspline

Hi,

I have two vectors, X, and Y (of same size).

Now, I am interested in cubic spline fit of the data points (Y) at certain values (let's call this vector as "x") by the code:

——————————-

x = 1:1:125;

y = interp1(X,Y, x,'spline')

plot(x,y,'–r')

——————————-

PLEASE CONFIRM:

The "plot (x,y,'–r')" command will give the cubic spline fit for data points (represented in Y), right?

Best Answer

right. You can verify this by

plot(X,Y,,'.',x,y);legend('Samples','Spline')

Related Solutions

MATLAB: Does the INTERP1 function in MATLAB handle complex data with the “cubic” method

This enhancement has been incorporated in Release 2006a (R2006a). For previous product releases, read below for any possible workarounds:

The cubic interpolation algorithm is not intended for complex data and hence does not behave well under certain circumstances when the data is complex. As a workaround, use the spline interpolation instead.

Y_spline = interp1(X,Y,Xi,'spline');
plot(X,abs(Y),'b',Xi,abs(Y_spline),'r')

Alternatively, you can split Y into real and imaginary parts, and then interpolate.

Yr = real(Y);
Yi = imag(Y);
Y_cubic = interp1(X,Yr,Xi,'cubic')+i*interp1(X,Yi,Xi,'cubic');
plot(X,abs(Y),'b',Xi,abs(Y_cubic),'r')

MATLAB: Confirm the number of dimensions

Try this:

cityNumber = data(:, 1);
numCoordinates = size(data, 2) - 1; % should be 2 or 3
x1 = data(:,2);
x2 = data(:,3);
if numCoordinates >= 3
	x3 = data(:,4);
end

if numCoordinates == 2
	plot(x1, x2, 'x', 'MarkerSize', 10);
	caption = '2 Coordinates';
elseif numCoordinates == 3
	plot3(x1, x2, x3, '*', 'MarkerSize', 10);
	caption = '3 Coordinates';
end
grid on;
xlabel('x1', 'FontSize', 20);
ylabel('x2', 'FontSize', 20);
if numCoordinates == 3
	zlabel('x3', 'FontSize', 20);
end
title(caption, 'FontSize', 20);

Best Answer

Related Solutions

MATLAB: Does the INTERP1 function in MATLAB handle complex data with the “cubic” method

MATLAB: Confirm the number of dimensions

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