Manual

330 Functions and commands
Inverse Laplace Returns the inverse Laplace transform of an expression.
invlaplace(Expr,[Var],[IlapVar])
Example:
ilaplace(1/(x^2+1)^2) returns ((-x)*cos(x))/
2+sin(x)/2
FFT With one argument (a vector), returns the discrete Fourier
transform in R.
fft(Vect)
With two additional integer arguments a and p, returns the
discrete Fourier transform in the field Z/pZ, with a as primitive
nth root of 1 (n=size(vector)).
fft((Vector, a, p)
Example:
fft([1,2,3,4,0,0,0,0]) gives [10.0,-
0.414213562373-7.24264068712*(i),-
2.0+2.0*i,2.41421356237-1.24264068712*i,-
2.0,2.41421356237+1.24264068712*i,-2.0-2.0*i]
Inverse FFT Returns the inverse discrete Fourier transform.
ifft(Vector)
Example:
ifft([100.0,-52.2842712475+6*i,-
8.0*i,4.28427124746-
6*i,4.0,4.28427124746+6*i,8*i,-52.2842712475-
6*i])
gives
[0.99999999999,3.99999999999,10.0,20.0,25.0,2
4.0,16.0,-6.39843733552e-12]
Solve
Solve Returns a list of the solutions (real and complex) to a
polynomial equation or a set of polynomial equations.
solve(Eq,[Var]) or solve({Eq1, Eq2,…},
[Var])
Examples:
solve(x^2-3=1) returns {-2,2}
solve({x^2-3=1, x+2=0},x)
returns {-2}