OOP: Select Data with conditional
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I would like to filter a array of objects (animal class) and get a new array of objects that fits in 2 properties conditions simultaneally.
Example:
I want to get all animals that have more than 5 years old and less than 10 inches of height.
My animal class is:
classdef animal
properties
age % years
height % inches
name % string
end
end
So I can create animals objects like
dog1 = animal();
dog1.age = 10;
dog1.height = 15;
dog1.name = "Bob";
cat1 = animal();
cat1.age = 2;
cat1.height = 10;
cat1.name = "Alice";
And than put all animals objects in same array, like:
my_array = {dog1, cat1, ...};
How can I "filter" my_array using 2 conditionals (age and height)?
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採用された回答
Luna
2018 年 11 月 27 日
Hi Nycholas,
Try this code below. Filtered array will return to you Jessie and Kayle which meets the conditions.
dog1 = animal();
dog1.age = 10;
dog1.height = 15;
dog1.name = 'Bob';
cat1 = animal();
cat1.age = 2;
cat1.height = 10;
cat1.name = 'Alice';
dog2 = animal();
dog2.age = 10;
dog2.height = 8;
dog2.name = 'Jessie';
cat2 = animal();
cat2.age = 6;
cat2.height = 3;
cat2.name = 'Kayle';
my_array = {dog1, cat1,dog2,cat2};
idx = logical(zeros(1,numel(my_array)));
for i = 1:numel(my_array)
if my_array{i}.age > 5 && my_array{i}.height < 10
idx(i) = true;
end
end
filteredArray = my_array(idx);
4 件のコメント
Luna
2018 年 11 月 29 日
編集済み: Luna
2018 年 11 月 29 日
It does nothing to do with OOP, I think what you need is a kind of table structure for that magical way below.
filtered_array = some_function(my_array, midi_note = 50, duration > 10, instrument = "Piano")
You should set a good defined tables for what you need or be using a database.
(You can still continue to use OOP)
その他の回答 (1 件)
Matt J
2018 年 11 月 29 日
編集済み: Matt J
2018 年 11 月 29 日
In this scenario, it is better to have a single object whose properties are arrays than an array of objects whose properties are scalars. However, the following should be faster than looping,
my_array = [my_array{:}]; %get rid of cell array storage
conditions = [my_array.age]>5 & [my_array.height]<10;
filtered_array = my_array(conditions);
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