Comparing Dataset

2012 5 9
1 个回答
回答已采纳
12 次查看（30 天）

0 个投票

Hi everyone,
I'm a newbie in matlab.
I have two big datasets with different number of row but same number in column. I need to compare each element of both datasets with reference of column #1. If column #1 in both data set has exactly the same value then subtract column 2 in 1st dataset with 2nd dataset.
Let says:
dataset1 = [1 2; 2 2; 3 5; 4 2; 5 10]; dataset2 = [1 4; 3 2; 5 2];
and the result that I want is:
result = [1 -2; 3 3; 5 8]
How can I solve this? Thanks in advance.

请先登录，再回答此问题。

 采纳的回答

Walter Roberson
Walter Roberson 2012-5-9

0 个投票

Use the three-output version of ismember to figure out which columns match which.

4 个评论
显示 2更早的评论 隐藏 2更早的评论

Mr D
Mr D 2012-5-9
Hi Walter,
Thanks for fast reply..Yes, I can define the correlation between two dataset, but when I try to do the operation between these datasets, it doesn't give me the result what I want.
Here my if statement:
dataset1 = [1 2; 2 2; 3 5; 4 2; 5 10];
dataset2 = [1 4; 3 2; 5 2];
is_mem = ismember(dataset1(:,1),dataset2(:,1));
delta = zeros(size(dataset1(:,1)));
for i =1:size(dataset1)
if (is_mem(i,1) == 1);
delta(i,1) = dataset1 (i,2) - dataset2 (i,2);
end
end
Could you give me a suggestion about this?
Thanks
Walter Roberson
Walter Roberson 2012-5-9
You only used the single-output version of ismember(). Please read the documentation for ismember() and look at the additional outputs that are available.
Mr D
Mr D 2012-5-9
I modified my code,
dataset1 = [1 2; 2 2; 3 5; 4 2; 5 10];
dataset2 = [1 4; 3 2; 5 2];
[is_mem,loc] = ismember(dataset2(:,1),dataset1(:,1));
delta = zeros(size(dataset2(:,1)));
for i = 1:size(dataset2)
for j= 1: size(dataset1)
if (loc(i,1) ~= 0);
delta(i,1) = dataset1 (j,2) - dataset2 (i,2);
end
end
end
and the result is still not what I want.
delta = [6;8;8]
the delta what I want is [-2,3,8].
What's wrong with my code?I'm really newbie in coding, could you give me more clear solution?
Thanks.
Mr D
Mr D 2012-5-9
Hi Walter,
Finally I can get the result what I want in simple code:
dataset1 = [1 2; 2 2; 3 5; 4 2; 5 10];
dataset2 = [1 4; 3 2; 5 2];
[is_mem,loc] = ismember(dataset2(:,1),dataset1(:,1));
v = dataset1(loc,2);
delta = dataset1(loc,2) - dataset2(:,2);
Thanks

请先登录，再进行评论。

更多回答（0 个）

类别

在 帮助中心 和 File Exchange 中查找有关 Phased Array Design and Analysis 的更多信息

标签

Community Treasure Hunt

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

Start Hunting!

Translated by