sum separate continuous values

Question

soe thiha 2020-9-27

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/600910-sum-separate-continuous-values

评论： per isakson 2020-9-28

Hello Matlab Senior Users

I have a column of data 0 and 1 and the example data is like this format. There are 2 number of continous 1 value group. I don't want all groups of 1 values. I need only the number of continuous 1 value groups. It is 2 for this sample data (index 3 to 4 and index 6 to 8).

I tried some code like this suggested by some expert. But the answer is not correct.

ids=find(x==1);
choice=diff(ids)~=1;
ids([true;choice])
indexes=ids([true;choice]);
groups=numel(indexes)

If someone kindly advice me in for loop or while loop if will helpful for me.

Thank you very much for your helps.

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Answer 1

per isakson 2020-9-28

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/600910-sum-separate-continuous-values#answer_501397

编辑：per isakson 2020-9-28

%%
d   = diff( c );
ixb = find( d == +1 ) + 1;
ixe = find( d == -1 );
%%
is_group = ixe >= ixb + 1;
[ ixb(is_group), ixe(is_group) ]

outputs

where

c is the column of your question
the first column of ans are indicies of the first "one" in a group and the second column the last.

Test this script with other input columns.

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soe thiha 2020-9-28

编辑：per isakson 2020-9-28

Dear Per Isakson

Thank you very much for your helps.

If you don't mind, may I request a next small question please?

Now I got the number of continuous 1 values groups. But, if I want to get the maximum value corresponding to the continuous groups, how can I do that please? I cannot use the value that is corresponding to 0 or individual 1 values. I have to find the max value within the continuous 1 groups .Follow is the sample data in which the answer is 2234.18.

  value  index 
85  0 
95  1 
62  1 
16  1 
09  1 
44  0 
19  0 
79  1 
86  0 
18  1 
63  1 
04  0 
04  1 
14  1 
39  1 
04  1 
09  1 
24  1 

per isakson 2020-9-28

%%
d   = diff( value_index(:,2) );
ixb = find( d == +1 ) + 1;
ixe = find( d == -1 );
%%
if ixb(end) > ixe(end)  % the last group includes the last row of value_index
    ixe(end+1) = size( value_index, 1 );
end
%%
is_in_group = false( size(value_index,1), 1 );
for jj = 1 : numel( ixb )
    is_in_group( ixb(jj) : ixe(jj) ) = true;
end
%%
max_value_in_groups = max( value_index( is_in_group, 1 ) );