dftmag

Magnitude of a discrete Fourier Transform (dFT) function.

Syntax

dftmag(vec_expr)

Argument

vec_expr
A valid vector expression.

Examples

Curve Math Vectors Result
x = dfreq(c1.x)

y = dftmag(c1.y)

Given c1, a curve is created that is the amplitude spectrum of the discrete Fourier Transform of c1.
Curve Math Vectors Result
fold(dfreq(c1.x))/2

fold(dftmag(c1.y))/(numpts(dfreq(c1.x)))

Given c1, normalize the output by dividing the results by the number of points.

Comments

The dftmag function returns the magnitude of a discrete Fourier Transform (dFT). The dFT is complex-valued and used to map time-domain data into the frequency domain. vec_expr_1 is assumed to be evenly sampled. The resultant vector has a number of elements equal to the number of elements in vec_expr.

The result (amplitude) of dftmag is dependent on the frequency/sampling.