How do I find the number of occurrences of data points between specific values in a matrix?

1 次查看（过去 30 天）
Joe
Joe 2015-12-9
评论： Joe 2015-12-14
The following code finds the number of occurrences of data between two points of the same value.
x=[4 1 2 2 2 2 2 2 2 2 2 4 1 2 2 2 2 3 3 4 5 6 1 2 2 2 2 2 2 2 2 2 2 2 3 4 1 2 2 2 2 2];
t=data==8;
out=diff(find(t))-1;
How could one change this code to determine how many data points are between specified data points to choose between?
for example:
If I had this code and I wanted to find the interval between the "1" and the next "4" in sequence how would I go about doing it? I want the code to output the interval of data points between the two specific values for each of the occurrences. From the data given as X the output should be output=[9 6 12]
Any help would be appreciated
  2 个评论
dpb
dpb 2015-12-9
How much is known of the data structure a priori? Specifically, is it known the values exist in sequence as shown here (albeit a missing closing '4' after the last initial '1')?
Joe
Joe 2015-12-14
this is just an example data set but the one I normally work with is a 1x600 matrix consisting of values between 1 and 10. It is known that these values occur in a semi-structured way. for example a 1 always precedes a 2 but a 1 can occur without being followed by a 2. I wanted a way to specifically target two numbers in a sequence and find their difference. The problem I am finding is that when I type in the code:
data=[1 2 2 2 2 2 2 2 2 2 3 1 2 2 2 2 7 8 3 8 3 4 5 6 1 2 2 2 ...
2 2 2 2 2 2 2 2 3 4 1 2 2 2 2 2];
PEI1=data== 1;
PEI3=data==3
PEI1out=diff(find(PEI1-PEI3))-1
it gives me a half right answer PEIout= [9 0 6 1 3 11 1], where the 9, 6, and 11 are correct but the others are not.

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Andrei Bobrov
Andrei Bobrov 2015-12-14
data = [1 2 2 2 2 2 2 2 2 2 3 1 2 2 2 2 7 8 3 8 3 4 5 6 1 2 2 2 ...
2 2 2 2 2 2 2 2 3 4 1 2 2 2 2 2];
x = [1 3];
[l1,ii] = ismember(data,x);
i0 = find(l1);
k = strfind(ii(i0),[1 2]);
out = diff([i0(k);i0(k+1)])-1;

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Resizing and Reshaping Matrices 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by