Question

我在Matlab中有一个基本问题。我需要输入一个二进制信号并输出一个二维数组，其中第一列是顺序出现的次数，第二列是它的值。

例如：

>> arr = [0;0;0;1;1;1;0];
>> tokenizeSignal(arr)

ans = 
3   0
3   1
1   0

连续三个0，然后连续三个1，然后一个0.

Answer 1

您想要的是游程编码。这是一种方法：

ind = [true; diff(arr)~=0]; % logical index of values that start runs
len = diff([find(ind); numel(arr)+1]); % run lengths
result = [len arr(ind)]; % build result

Answer 2

这是一种实现此目的的简单方法：

% input
arr = [0;0;0;1;1;1;0];

% make sure the input is a column vector (else the concatenation
% to create index won't work)
arr = arr(:);

% create an index that is 1 for the first group of equal values,
% 2 for the second group, etc.
index = 1 + cumsum([0 ; logical(diff(arr))]);

% use grpstats to determine how many of each index there are and
% what the unique value associated with that index is; using
% 'min' to determine unique value is fine since all the elements
% in a given group are equal
[count, value] = grpstats(arr, index, {'numel', 'min'});

% display the answer
disp([count, value])
    3     0
    3     1
    1     0

基本Matlab - 如何输出多少1和0的2D数组

2 个答案: