IMAG
Imag(X) returns the imaginary part of a complex variable X. Representing X as X_r + i*X_i, this function returns X_i.
Example: Y=Imag(X)
The above example will set the real part of Y (Y_r) to the imaginary part of X and the imaginary part of Y to zero.
Note that the Imag function is used to extract the imaginary part of a complex number variable or expression. It cannot be used for assigning the imaginary part of a complex number. For example, the equation Imag(X)=4 will produce an error. Instead you should just enter X=4*i which will set X to 0 + 4*i. If you wish to only set the imaginary part of X, you can enter
X_i=4.0
See also: Real, Magnitude, Angle, CIS, Complex Numbers, Mathematical Functions