[R] equivalent function to MatLab 'step' ?

[Carl Witthoft]

Well, I found out part of the confusion:

The modern versions of MatLab renamed their function from 'step' to 
'stepz' .

Stepz(num,den) provides a calculation of the time-response to a step 
function based on the system state equation defined by the num and den 
coefficients.

So, is there some R function (maybe inside some of the TS packages) 
which do similar Laplace-transform-related calculations?

thanks
Carl