フィルターのクリア

Minimum value with row index

2 ビュー (過去 30 日間)
Mohammad Yunus Ali
Mohammad Yunus Ali 2011 年 3 月 29 日
I wrote the following code to get a minimum positive value and the row index as well but the output is giving wrong row index. Anyone can help me?
The answer should be...minba=0.005 ri=9
clc; clear all;
ba=[52 15 52 44 44 0 -25 -4 .05]; [minba ri]=min(ba((ba>0)))

採用された回答

Sean de Wolski
Sean de Wolski 2011 年 3 月 29 日
idx = min(find(ba==minba))
  2 件のコメント
Walter Roberson
Walter Roberson 2011 年 3 月 29 日
idx = find(ba==minba,1);
Matt Fig
Matt Fig 2011 年 3 月 29 日
I understand the question to be "How do I find the minba and ri," not, "Given, minba, how to find the ri?"

サインインしてコメントする。

その他の回答 (2 件)

Matt Fig
Matt Fig 2011 年 3 月 29 日
If minba is not known before hand (the general case, and what it sounds like you want to have), then:
ba = [52 15 52 44 44 0 -25 -4 .05]; % Your data...
ba(ba<=0) = inf; % Take non-positive values out of the picture.
[minba,ri] = min(ba) % Find the min and index.
minba =
0.05
ri =
9
A faster alternative to the above, if the number of non-positives is a large fraction of the whole:
minba = min(ba((ba>0)));
ri = find(ba==minba,1);
  3 件のコメント
Matt Fig
Matt Fig 2011 年 3 月 29 日
How would you use FIND if minba wasn't known before hand? I think anything that could do this using FIND would be slower than what I showed...
Matt Fig
Matt Fig 2011 年 3 月 29 日
But I was wrong. This is faster indeed, when the number of non-positives is a large fraction of the whole:
minba = min(ba((ba>0)));
ri = find(ba==minba,1);

サインインしてコメントする。


Walter Roberson
Walter Roberson 2011 年 3 月 29 日
idx = find(ba > 0,1);
minba = ba(idx);
  5 件のコメント
Sean de Wolski
Sean de Wolski 2011 年 3 月 29 日
Congrats Walter on your 1000th answer!
Matt Fig
Matt Fig 2011 年 3 月 29 日
@Walter
Qouting the OP (without quotes of course)
I wrote the following code to ...
The answer _should_ _be_...minba=0.005 ri=9
So I assume Mohammad wanted to be shown the _correct_ way to get both minba and ri.

サインインしてコメントする。

カテゴリ

Help Center および File ExchangeLogical についてさらに検索

タグ

Community Treasure Hunt

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

Start Hunting!

Translated by