歐氏距離的MATLAB實現
問題描述
實現任意給定兩個相同維度的向量之間的歐氏距離計算函數dist_E(x,y)。
測試代碼:x=[1,3,0,2]; y=[2,3,2,0]; dist=dist_E(x,y);
代碼實現
實現程序如下圖所示:
% 方法1
function dist = dist_E(x,y)
dist = [];
if(length(x)~=length(y))
disp('length of input vectors must agree') % disp函數會直接將內容輸出在Matlab命令窗口中
else
z =(x-y).*(x-y);
dist = sqrt(sum(z));
end
end
% 方法2:公式法
function dist = dist_E(x,y)
[m,n] = size(x);
dist = 0;
for i=1:max(m,n)
dist = dist+(x(i)-y(i))^2;
end
dist = sqrt(dist);
end
% 方法3:採用pdist函數
function dist = dist_E(x,y)
dist = [x;y];
dist = pdist(dist); % 計算各行向量之間的歐式距離
end
命令行窗口輸入如下代碼:
x=[1,3,0,2];
y=[2,3,2,0];
dist=dist_E(x,y)
代碼執行結果: