# sum separate continuous values

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soe thiha on 27 Sep 2020
Commented: per isakson on 28 Sep 2020
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).
0
0
1
1
0
1
1
1
0
1
0
1
0
0
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.

per isakson on 28 Sep 2020
Edited: per isakson on 28 Sep 2020
%%
d = diff( c );
ixb = find( d == +1 ) + 1;
ixe = find( d == -1 );
%%
is_group = ixe >= ixb + 1;
[ ixb(is_group), ixe(is_group) ]
outputs
ans =
3 4
6 8
>>
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.

per isakson on 28 Sep 2020
"total number of groups" that's given by the number of rows of the output matrix. Thus, use
number_of_groups = size( output_of_script, 1 );
soe thiha on 28 Sep 2020
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
849.85 0
799.95 1
946.62 1
801.16 1
857.09 1
829.44 0
1569.19 0
2234.79 1
2168.86 0
2234.18 1
1556.63 1
962.04 0
838.04 1
774.14 1
827.39 1
754.04 1
857.09 1
915.24 1
per isakson on 28 Sep 2020
%%
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 ) );
where value_index is the table of your comment.