pp2@nereida:~/.ssh$ perl -wde 0
main::(-e:1):   0
  DB<1> use PDL
  DB<2> use PDL::Complex
  DB<3> $x = r2C(-27)    # From real to complex
  DB<4> $r = Croots $x, 3 # There are three complex roots  
  DB<5> print $r     # It is sad that there is a bug 
                     # with "" overload
Use of uninitialized value in numeric ...
[
  1.5 +2.59807621135332i  
 -3 +3.67381906146713e-16i  
  1.5 -2.59807621135332i
]
  DB<6> x $ra      # The answer is a PDL object
0  PDL::Complex=SCALAR(0x8a6a0a8)
   -> 144899352
  DB<7> p re $r  # Get the "real" components
[1.5 -3 1.5]
  DB<8> p im $r  # And the imaginary ones:
[ 2.5980762 3.6738191e-16 -2.5980762]
  DB<9> $y = $r ** 3 # Check the solution:
  DB<10> p re $y
[-27 -27 -27]
  DB<11> p im $y  # Almost 0, as expected
[3.3064372e-15 9.9193115e-15 6.8636015e-14]