I Presented problems for the plot "DB magnitude spectrum."
The structure of vector data spec has the following configuration,Float (-infinity), inside.
N := 64;
T := 1;
f := .25;
A := 1;
phi := 0;
n := Vector(N, -> i-1, datatype = complex[8]);
x := cos~(2*Pi*n*f*T);
X := DiscreteTransforms[FourierTransform](x, normalization = none);
magX := abs(X)
fn := Vector(N, i-> evalf((i-1)/N) );
DynamicSystems:-DiscretePlot(fn, magX, style = stem, color = blue, labels = ["Normalized Frequency (cycles per sample)", "Magnitude (Linear)"], labeldirections = ["horizontal", "vertical"]);
spec := 20*log10~(magX)
plot(<fn| spec>, view = [0 .. 1, -350 .. 50])
The expected graph is as follows:
How to do it?
Gracias
