Basics of MATLAB and Beyond

x = linspace(-1,1,8192);Fs = 1000;y = vco(x,[0 500],Fs);plot(y(1:1000))axis([0 1000 -5 5])zeroaxesWe used the axis command to set the y-axis limits to [-5 5] insteadof the default limits, in this case, of [-1 1]clfplot(y(1:1000))which makes the variation in frequency slightly less apparent, and isjust too grandiose. The eye can pick up very subtle variations in linestraightness, but here the variation is so huge that the lines becomeparallel and begin to produce the optical illusion of vibration. Also,lines that are very nearly vertical or horizontal begin to be affected bythe finite resolution of dot printers. Using Handle Graphics we canachieve a more elegant result by reducing the height of the y-axis. Wedo this by setting the position property of the current axes:set(gca,’Position’,[.1 .5 .8 .1],’box’,’off’)The gca input is itself a function, which returns the handle to the currentset of axes. We are saying that we want to set the position of the currentaxes to be equal to the vector [.1 .1 .8 .1]. The position vector hasthe form [left, bottom, width, height ], in units normalised to thefigure window; (0, 0) is the bottom left and (1, 1) is the top right. Butperhaps we should shrink it even further, and dispense with the everpresentaxes:set(gca,’Position’,[.1 .5 .8 .01],’visible’,’off’)c○ 2000 by CRC Press LLC