Function File: scatterplot (x)
Function File: scatterplot (x, n)
Function File: scatterplot (x, n, off)
Function File: scatterplot (x, n, off, str)
Function File: scatterplot (x, n, off, str, h)
Function File: h = scatterplot (…)

Display the scatter plot of a signal. The signal x can be either in one of three forms

A real vector

In this case the signal is assumed to be real and represented by the vector x. The scatterplot is plotted along the x axis only.

A complex vector

In this case the in-phase and quadrature components of the signal are plotted separately on the x and y axes respectively.

A matrix with two columns

In this case the first column represents the in-phase and the second the quadrature components of a complex signal and are plotted on the x and y axes respectively.

Each point of the scatter plot is assumed to be separated by n elements in the signal. The first element of the signal to plot is determined by off. By default n is 1 and off is 0.

The string str is a plot style string (example "r+"), and by default is the default gnuplot point style.

The figure handle to use can be defined by h. If h is not given, then the next available figure handle is used. The figure handle used in returned on hout.

See also: eyediagram.

Demonstration 1

The following code

 n = 200;
 ovsp = 5;
 x = 1:n;
 xi = [1:1/ovsp:n-0.1];
 y = randsrc (1, n, [1 + i, 1 - i, -1 - i, -1 + i]);
 yi = interp1 (x, y, xi);
 noisy = awgn (yi, 15, "measured");
 h = scatterplot (noisy);
 hold on;
 scatterplot (noisy, ovsp, 0, "r+", h);

Produces the following figure

Figure 1

Package: communications