unu 3op: Ternary operation on three nrrds or constants. Can have one, two, or
three nrrds, but not zero. Use "-" for an operand to signify a nrrd to be read
from stdin (a pipe). Note, however, that "-" can probably only be used once
(reliably).
Usage: unu 3op <operator> <in1> <in2> <in3> [-t <type>] [-o <nout>]
<operator> = Ternary operator. Possibilities include:
o "clamp": second value is clamped to range between the first
and the third
o "lerp": linear interpolation between the second and third
values, as the first value varies between 0.0 and 1.0,
respectively
o "exists": if the first value exists, use the second value,
otherwise use the third
o "between": 1 iff second value is >= first and <= second, 0
otherwise
<in1> = First input. Can be float or nrrd.
<in2> = Second input. Can be float or nrrd.
<in3> = Third input. Can be float or nrrd.
-t <type> = type to convert all nrrd inputs to, prior to doing operation.
This also determines output type. By default (not using this
option), the types of the input nrrds are left unchanged.
-o <nout> = output nrrd (string); default: "-"
