% Chapter 7 Figure mfile:
%           Mfile to draw figures on equiripplr amplitude response,
%                 error function, and weighted error function.
% a) equiripple amplitude response
figure(1); subplot(1,1,1)
f = [0,0.3,0.5,1]; m = [1,1,0,0]; weights = [0.5,1];
h = remez(10,f,m,weights);
M = length(h); n = 0:M-1;
[Hr,w,a,L] = Hr_Type1(h);
plot(w/pi,Hr);axis([0,1,-0.15,1.15])
xlabel('frequency in pi units');
title('Amplitude Response of an Equiripple Filter');hold on
wp = w(1:151); ws = w(251:501);
upb=Hr(1)*ones(length(wp),1);
lpb=(2-Hr(1))*ones(length(wp),1);
ipb=ones(length(wp),1);
plot(wp/pi,upb,'r',wp/pi,ipb,'g',wp/pi,lpb,'r')
usb=Hr(251)*ones(length(ws),1);
isb=zeros(length(ws),1);
lsb=-Hr(251)*ones(length(ws),1);
plot(ws/pi,usb,'r',ws/pi,isb,'g',ws/pi,lsb,'r');
set(gca,'XTickMode','manual','XTick',[0,0.3,0.5,1])
set(gca,'XTickLabelMode','manual','XTickLabels',[' 0 ';'0.3';'0.5';' 1 '])
set(gca,'XGrid','on')
set(gca,'YTickMode','manual','YTick',[-0.05,0,0.05,0.90,1,1.10])
set(gca,'YTickLabelMode','manual',...
        'YTickLabels',['-0.05';' 0.0 ';' 0.05';' 0.90';' 1.0 ';' 1.10'])
text(0.31,1,'Ideal Response');
text(0.32,0.0,'Ideal Response')
hold off
print -deps2 equir_ar.eps
%
% Error function plots
figure(2); clf; subplot(2,1,2); 
erpb=Hr(1:151)-ipb; ersb=Hr(251:501)-isb;
plot(wp/pi,erpb,ws/pi,ersb); axis([0,1,-.15,.15]);
xlabel('frequency in pi units');
title('Error Function');hold on
plot(wp/pi,upb-ipb,'r',wp/pi,lpb-ipb,'r')
plot(ws/pi,usb-isb,'r',ws/pi,lsb-isb,'r');
set(gca,'XTickMode','manual','XTick',[0,0.3,0.5,1])
set(gca,'XTickLabelMode','manual','XTickLabels',[' 0 ';'0.3';'0.5';' 1 '])
set(gca,'XGrid','on')
set(gca,'YTickMode','manual','YTick',[-0.1,-0.05,0,0.05,0.1])
set(gca,'YTickLabelMode','manual',...
        'YTickLabels',['-0.10';'-0.05';' 0.0 ';' 0.05';' 0.10'])
%plot([0,0.5],[-0.05,-0.05],'-.')
hold off
print -deps2 errorfun.eps
%
% Weighted function plots
figure(3); clf; subplot(2,1,2); 
werpb = weights(1)*erpb; wersb = weights(2)*ersb;
plot(wp/pi,werpb,ws/pi,wersb); axis([0,1,-.1,.1]);
xlabel('frequency in pi units');
title('Weighted Error Function');hold on
plot(wp/pi,weights(1)*(upb-ipb),'r',wp/pi,weights(1)*(lpb-ipb),'r')
plot(ws/pi,weights(2)*(usb-isb),'r',ws/pi,weights(2)*(lsb-isb),'r');
set(gca,'XTickMode','manual','XTick',[0,0.3,0.5,1])
set(gca,'XTickLabelMode','manual','XTickLabels',[' 0 ';'0.3';'0.5';' 1 '])
set(gca,'XGrid','on')
set(gca,'YTickMode','manual','YTick',[-0.05,0,0.05])
set(gca,'YTickLabelMode','manual',...
        'YTickLabels',['-0.05';' 0.0 ';' 0.05'])
text(0.08,0.075,'weight = 0.5')
text(0.70,0.075,'weight = 1.0')
hold off
print -deps2 wterrfn.eps