find maximum value for each year in a 2 columns array

1 次查看（过去 30 天）

Mahtab Moalemi 2020-4-16

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/518302-find-maximum-value-for-each-year-in-a-2-columns-array

评论： Mahtab Moalemi 2020-4-16

I have an array with two columns, column one year (1975-2020) and column two discharge values. I need to find the maximum discharge amount for each year and have them saved in another matrix.

Can you please help me with this?

input:

1975 200

1975 85

2002 110

2002 95

2002 32

...

2020 120

...

desired output

1975 200

...

2002 110

...

2020 120

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。

采纳的回答

Tommy 2020-4-16

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/518302-find-maximum-value-for-each-year-in-a-2-columns-array#answer_426350

在 MATLAB Online 中打开

Try this:

[G, y] = findgroups(input(:,1));
output = [y splitapply(@max, input(:,2), G)];

5 个评论
显示 3更早的评论隐藏 3更早的评论

Tommy 2020-4-16

编辑：Tommy 2020-4-16

在 MATLAB Online 中打开

Switch the outputs.

[groups, years] = findgroups(year_Q(:,1));
>> output = [years splitapply(@max, year_Q(:,2), groups)];

Mahtab Moalemi 2020-4-16

nevermind! sorted it out

Thanks

请先登录，再进行评论。

类别

MATLAB Language Fundamentals Matrices and Arrays Shifting and Sorting Matrices

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

Community Treasure Hunt

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

Start Hunting!

Translated by