How to write code for a function x(t), consist of two sine wave with instantaneous frequencies at different time spot as seen in figure below:

Could any one help me how to write the Matlab code for this function in order to plot the Hilbert spectrum?

Answer 1

[Stephan]

syms t
y = piecewise((0<t)&(t<=2), sin(2*pi*5*t), (2<t)&(t<=5), sin(2*pi*40*t))
fplot(y)

[Jan Ali]

Thanks a lot Stephan. Any idea for plotting the Hilbert spectrum of y?

[Stephan]

I dont hve access to the signal processing toolbox - but here is a link that might help:

https://de.mathworks.com/help/signal/ref/hht.html