make_plot.m

自适应滤波器原理matlab程序

function make_plot(v, w, rp, Nlevs, xlim, ylim, str1, str2)

% function make_plot(w, v, rp, Nlevs, xlim, ylim)

r0 =  1;
r1 = -(rp.a1/(1+rp.a2));
R  =  [r0 r1; r1 r0];
wo = [-rp.a1; -rp.a2];

% set limits on plotting and determine grid
res   = 0.1;
xl=max([xlim ylim]); yl=xl;
x_ind =  -xl:res:xl;    V1 = x_ind(ones(length(x_ind),1), :);%每个点都产生length(x_ind)个构成一列，共length(x_ind)列
y_ind = [-yl:res:yl]';  V2 = y_ind(:, ones(length(y_ind),1));%每个点都产生length(y_ind)个构成一行，共length(y_ind)行

Jv    = rp.Jmin + rp.lam1*V1.^2 + rp.lam2*V2.^2;	% calculate error surface wrt v，使用V1的一行和V2的一列画一个椭圆，V1和V2都是方阵

for i=1:length(x_ind),
     for j=1:length(y_ind),
      wb=[x_ind(i); y_ind(j)];
      Jw(j,i) = rp.Jmin + (wb-wo)'*R*(wb-wo);
   end
end

% determine values for first Nlevs contours (for given n)，确定前Nlevs条等高线的值
levsv  = rp.lam1*v(1,1:Nlevs).^2 + rp.lam2*v(2,1:Nlevs).^2+rp.Jmin;%前Nlevs条椭圆轨道等高线

% do the plotting
figure(1)
p1_h=plot(v(1,:), v(2,:),'linewidth',2);%式4.34曲线收敛运动轨迹
xlabel('v_1'); ylabel('v_2'); hold on;%hold on 在当前图基础上继续画图，hold off复位画图默认值
contour(V1(1,:), V2(:,1),flipud(Jv), levsv,'k'); hold off;%画前Nlevs条椭圆轨道等高线，flipud对矩阵上下翻转，本例程中要flipud与否无影响，levsv确定了等高线的值，只画Nlevs条
set(gca,'xlim',[-xlim xlim])    %xlim定义坐标轴的极限，set用于设置坐标轴的特性，gca用于返回当前轴的句柄
set(gca,'xlim',[-ylim ylim])
set(get(gca,'title'),'string',str1);%get用于获得已有轴的各种特性，此set用于设置标题

figure(2)
p2_h=plot(w(1,:), w(2,:),'linewidth',2);%式4.37曲线收敛运动轨迹
xlabel('w_1'); ylabel('w_2'); hold on;
contour(x_ind, y_ind, Jw, levsv,'k'); hold off
set(get(gca,'title'),'string',str2);

% note that Jw did not need flipping - this was taken care of by the 
% index shuffle in the line that assigns values to Jw in the double
% loop up above

if nargin > 5,%nargin 输入参数的个数
   for i=1:2,
      figure(i)
      set(gca, 'Xlim', [-xlim xlim])
      set(gca, 'Ylim', [-ylim ylim])
      line([-xlim xlim], [0 0])
      line([0 0], [-ylim ylim]) 
      end
end