frequency.m

来自「常用图像压缩编码码matlab实现。包括：DM编码、变换编码（FFT和DCT）、」· M 代码 · 共 13 行

function f = frequency(vector)
%函数frequency计算各符号出现的概率

if ~isa(vector, 'uint8')
    error('input argument must be a uint8 vector');
end
f = repmat(0, 1, 256);
len = length(vector);
for index = 0:255
    f(index+1) = sum(vector == uint8(index));
end
f = f./len;   %归一化