Imag Part

Shipping

imag_part

Extract the imaginary part Im(z) of a complex array (zeros for real input)

Signature

Inputs

zArray|Complex|Scalarrequired— Complex or real input. A real input yields an all-zero array of matching length.

Outputs

imArray— Real array = Im(z), keeping z's unit; zeros when z is real.

Description

Imag Part returns $ℑ (z)$ — the imaginary component of a complex array — as a real array, keeping z's physical unit. It is the complement of Real Part (real_part).

For a real input it returns an array of zeros the same length (the imaginary part of a real number is zero) rather than erroring — so it is safe on any array. The node is stateless.

Mathematics

im_{k} = ℑ (z_{k})

real input: im_{k} = 0 \forall k

Examples

Extract the quadrature channel

Feeding $[3 + 4 i, 1 - 1 i]$ into z yields $[4, - 1]$ on im. A real $[1, 2]$ yields $[0, 0]$ .

Applications

Recovering the sine / quadrature component of an analytic or I/Q signal.
Inspecting the imaginary residue of an inverse-FFT result as a numerical-error diagnostic.
Building phase-sensitive detectors from complex baseband data.

Neat

A real input synthesizes a zeros vector matched to the real length rather than failing, so 'imag_part' never errors on real arrays.