testsinecosine.m

Cordic算法的Matlab实现

%% Test sine/cosine
%   0<z0<pi/2
%   test cordic

clc,clear all
theta=linspace(0,pi/2,100)';
% function [xn,gain,Fs,Ds,yn,zn]=cordic(x0,y0,z0,mode,...
%                                    dv_n,ROM,wordwidth)
wordwidth=64;
Fs=-ones(wordwidth,length(theta));
Ds=zeros(size(Fs));
n=-(0:64)';ROM=[-n,atan(2.^n)];
for i=1:length(theta)
    [xn(i),An(i),F,D,zn(i),yn(i)]...
   =cordic(1,0,theta(i),1,'z',ROM);
    Fs(1:length(F),i)=F;
    Ds(1:length(D),i)=D;
    %sprintf('theta=%f',theta(i))
end
cosine=xn./An;
sine=yn./An;
true_cosine=cos(theta);% true values
true_sine=sin(theta);
%theta=theta/pi*180;
figure(1),hold on
plot(theta,cosine,'LineWidth',1.5)
plot(theta,sine,'LineWidth',1.5)
plot(theta,true_cosine,'g')
plot(theta,true_sine,'g')
plot(theta,true_cosine-cosine','r')
plot(theta,true_sine-sine','m')
plot(theta,zn,'y')
legend('Cordic cosine','Cordic sine',...
       'true cosine','true sine',...
       'error cosine','error sine','zn')
xlabel('\theta'),ylabel('value')
hold off
% some statistics
save F1.dat Fs -ascii
save D1.dat Ds -ascii