how to find Laplace transform of u(-t) in MATLAB?

To find LT of u(-t) I am trying the following code

f = heaviside(-t)
x = laplace(f)

However I am always getting 0 as output.

Answer 1

[Paul]

Hi Sundaram,

The function laplace implements the unilateral Laplace transform for causal signals. However, heaviside(-t) is non-causal, so presumably you want the bilateral Laplace transform.

For this problem, you can compute the bilateral Laplace trasform by combining laplace and subs using the time reversal property of the Laplace transform.

Or, you can compute the bilateral Laplace transfrorm using int to compute the bilateral Laplace transform via its defining integral. You will have to use assume to properly define the region-of-convergence to yield the expected result.

[sundaram kaliyugavaratharajan]

That works. Thanks Paul