Find and collate matching values.

4 次查看（过去 30 天）
Abhi Ove
Abhi Ove 2017-10-9
评论： Abhi Ove 2017-11-13
Hi All,
Lets say I have multiple unique data sets:
data1.gamma = [1,2,3,4,5,6,7,8,9,10];
data1.eta = [0.1,0.4,0.9,0,0.2,0.5,0.7,0.8,0.9,0.10];
data1.phi ........
data2.gamma = [0,2,0,4,5,9,7,10,9,6];
data2.eta = [0.1,0.4,0.9,0,0.2,0.5,0.7,0.8,0.9,0.10];
data2.phi ........
and data3, data4 etc as such.
I would like to write a function that can to compare all the data sets and on each data set only keep variable values where
data.gamma
is the same. Any idea how I would go about doing that? I can compare and match 2 data sets. However I am not sure how to compare multiple data sets.
Also I do not know how many data set there will be (data1,data2,data3,data4....). So how do I make the function "scale-up" as necessary. Is that even possible without predefined the variable names?
Any help would be much appreciated.
  5 个评论
显示 3更早的评论
Jos (10584)
Jos (10584) 2017-10-12
Do *NOT* store your data like this. Use an array of structs.
data(1).gamma = ...
data(2).gamma = ...
Jos (10584)
Jos (10584) 2017-10-12
That being said, what is it you want to keep? Can you give a small example of input and required output?

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

Image Analyst
Image Analyst 2017-10-12
Not sure what "keep" means, but to compare the two arrays, use isequal(). Try this:
if isequal(data1.gamma, data2.gamma)
% They're equal
else
% They're not equal.
end
It would be best if your datan were not unique as you said, but a structure array. For example if you had 10 versions of data all with different names you'd have 10*9/2 = 45 separate if blocks to compare all possible pairs. If you had one variable, data, that was a structure array, then you don't need to compare all combinations pair-by-pair, but you could do a nested loop to make all comparisons:
for k1 = 1 : length(data)
for k2 = 1 : k1-1
if isequal(data(k1).gamma, data(k2).gamma)
% They're equal
else
% They're not equal.
end
end
end
  1 个评论
Abhi Ove
Abhi Ove 2017-11-13
Thanks a lot for your answer. I have found your advice very helpful. However I have implemented the following method which seems to work wonderfully.
Solution.

请先登录，再进行评论。

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Loops and Conditional Statements 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