@Carl Love 

@Carl Love 

The figure is attached 

@Carl Love 

Note that the figure will be display as in attached. I want to get codes for plotting those kinds of figures.

Please also note that (x,0,0,0) is a line of equilibria 

@Carl Love 

Thanks for considering, the initial w(0)=0, z(0)=0 can be taken.

@C_R 

Thanks for sharing Link, I attached the figure that I want to plot it. Is there any code to plot it? Please.