What do these different colors of stem plot indicates?

This is the stem plot for a complex value matrix of size 512x40. What does these different coluors indicates ?

How to unayse this stem diagrams?

What does the spacing of stem lines indicates ?

[Muhammad Usman]

I hope you can get answers from the given below code.

clear all;close all; clc
fig = figure;
x = linspace(1,3);
y = sin(x);
vectors = [complex(x, y)];
stem(real(vectors),imag(vectors),'Color',[1 0 0])
hold on;

Answer 1

[Walter Roberson]

complex value matrix of size 512x40

stem() applied to real() and imag() of that is going to create 40 different stem plots. The colors of those plots are chosen automatically if you do not use the Color parameter.

[Vishwaraj Manur]

What does STEM plot in MATLAB indicates? what does it indicates if stem( FFT(x(t))) of a signal x(t) is drawn ? What is its importance?