Sum row 2 and stop when 1 is reached in row 1

Question

Iris Willaert 2022-2-14

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1649805-sum-row-2-and-stop-when-1-is-reached-in-row-1

评论： Image Analyst 2022-2-17

采纳的回答： Image Analyst

Hi,

I have a array of two rows with the following numbers:

Row1: [0,0,1,0,0,0,1,0,0,1,0]

Row2: [0.0220,0.3110,0.0230,1.0550,0.0230,0.0456,0.1120,0.0400,0.0660,0.3690]

I want to take the sum of row 2: until row 1 contains 1.

for example: 0.0220+0.3110, 0.0230 + 1.0550 + 0.0230 +0.0456

I tried to do this with a loop but it doesn't give me want I want.

for i = Row1

if(i == 0)

sum(Row2)

break;

end

if(i == 1)

break;

end

can anyone help me with this?

Thanks a lot!

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Image Analyst 2022-2-14

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1649805-sum-row-2-and-stop-when-1-is-reached-in-row-1#answer_896100

在 MATLAB Online 中打开

Try using find():

Row1 =[0,0,1,0,0,0,1,0,0,1,0];
Row2 = [0.0220,0.3110,0.0230,1.0550,0.0230,0.0456,0.1120,0.0400,0.0660,0.3690];
oneIndexes = find(Row1 == 1)
oneIndexes = 1×3
     3     7    10
% Find out where each stretch starts and stops.
startIndexes = [1, oneIndexes]
startIndexes = 1×4
     1     3     7    10
stopIndexes = [oneIndexes - 1, length(Row2)]
stopIndexes = 1×4
     2     6     9    10
% Loop over each stretch, computing the sum in that stretch.
for k = 1 : length(startIndexes)
	index1 = startIndexes(k);
	index2 = stopIndexes(k);
	theSums(k) = sum(Row2(index1 : index2));
end
theSums % Show in command window
theSums = 1×4
    0.3330    1.1466    0.2180    0.3690

2 个评论
显示无隐藏无

Iris Willaert 2022-2-17

Briliant that did the job for me!

Thanks!

Image Analyst 2022-2-17

You're welcome. Can you click the "Accept this answer" link for the best answer and click the Vote icon for both answers. 🙂

请先登录，再进行评论。

Answer 2

David Hill 2022-2-14

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1649805-sum-row-2-and-stop-when-1-is-reached-in-row-1#answer_896095

编辑：David Hill 2022-2-14

在 MATLAB Online 中打开

m=  [0,0,1,0,0,0,1,0,0,1;0.0220,0.3110,0.0230,1.0550,0.0230,0.0456,0.1120,0.0400,0.0660,0.3690];
%rows of the same matrix must be the same size
f=[1,find(m(1,:))];
for k=2:length(f)
  s(k-1)=sum(m(2,f(k-1):f(k)-1));
end