Impulse Response of a piecewise function

Is it possible to take the impulse response of a piecewise function?

I am wanting to produce frequency and impulse responses for a plot with a roll off factor. My roll off factors have been defined as r1, r2, and r3 (being the ideal condition). I created a piecewise function to show the graph, but this shows it in the frequency domain.

When I use the ifft(ifftshift ) command to get the impulse response of my plot I get an error. Is there a way to make this work?

Note, the first half of my code works the way I want it to

%generate roll off plot
syms f
Pf1 = piecewise(abs(f)<(Rb/2)-fx1, 1, abs(f-Rb/2)<fx1, (1/2)*(1-sin(pi*((f-(Rb/2))/(2*fx1)))), abs(f)>(Rb/2)+fx1, 0);
Pf2 = piecewise(abs(f)<(Rb/2)-fx2, 1, abs(f-Rb/2)<fx2, (1/2)*(1-sin(pi*((f-(Rb/2))/(2*fx2)))), abs(f)>(Rb/2)+fx2, 0);
Pf3 = piecewise(abs(f)<(Rb/2)-fx3, 1, abs(f-Rb/2)<fx3, (1/2)*(1-sin(pi*((f-(Rb/2))/(2*fx3)))), abs(f)>(Rb/2)+fx3, 0);

figure
fplot(Pf1,'r')
axis([-5, 5, -5, 5]);
grid on
hold on
fplot(Pf2,'b')
hold on
fplot(Pf3,'k')
title('Frequency Response')
hold off

%Generate the impulse respnose
%Code up to this point works, error past this point

IR_Pf1 = ifft(ifftshift(Pf1));
IR_Pf2 = ifft(ifftshift(Pf2));
IR_Pf3 = ifft(ifftshift(Pf3));

figure
fplot(IR_Pf1,'r')
axis([-5, 5, -5, 5]);
grid on
hold on
fplot(IR_Pf2,'b')
hold on
fplot(IR_Pf3,'k')
title('Impulse Response')
hold off

Answer 1

[madhan ravi]

ifft() requires numerical approach wheras you feed in symbolic values therefore you need to convert the variables using subs() and then double() to make it of class double.

[Kaylyn Wessel]

How would you approach converting a piecewise function like this?

In my case I am not wanting to sub my old value with anything, but I am wanting to evaluate it from -5 to 5.

sub1 = subs(Pf1,f, [-5:.01:5]);
double1 = double(sub1);

This code seems to return what I am wanting, but if I substitude 'double1' into my code

IR_Pf1 = ifft(ifftshift(double1));

It gives me a large amount of errors in several referencing toolboxes