Performance improvement array of class instances

Hey there,

i have created a class called Test:

classdef test
    properties
        a
        b
        var1
        var2
        ID
    end   
    methods
        function obj = test(a,b,var1,var2)
            obj.a = a;
            obj.b = b;
            obj.var1 = var1;
            obj.var2 = var2;
        end
    end
end

Multiple Instances of this class are stored in a vector:

test1 = test(1,2,3,4);
test2 = test(1,3,5,7);
test3 = test(2,4,6,8);

all_tests = [test1,test2,test3];

I want to search for the test instance in all_tests, which has the a value of 1 and (of those remaining) the lowest possible b value.

This test instance is then used for further calculation and creation of additional test instances, which will be added to all_tests.

After that, this instance shall be deleted from all_tests.

I am currently using a probably very complicated method to accomplish all this:

% Search for instance with lowest possible b, while a==1
[curr_min, curr_min_index] = min([all_tests([all_tests().a]==1).b]); % finding the Minimum in a subset of all_tests
IDs = [all_tests([all_tests().a]==1).ID]; % I have used a unique ID, to find the index of the minimum in all_tests
currID = IDs(curr_min_index); %finding the ID of the Minimum
current_test = all_tests([all_tests().ID]==currID); %returns my desired test instance

% Next, i use this instance for calculations and create a new test instance
temp = test(current_test.var1,current_test.var2,1,2);

%This new instance is then added to all_tests:
all_tests(end+1,1)=temp;

%The old instance gets deleted from all_tests:
all_tests([all_tests().ID]==currID)=[];

It all works, but it is really slow.

I am pretty sure, there is a better way to do, what i tried to do.

Thank you

Answer 1

[Niklas Braun]

I solved my slow Minimum index search with this:

curr_min_index = find([test.b]==min([test([test().a]==1).b]) & [test.a]==1, 1, 'first');

Answer 2

[Steven Lord]

I would probably create a method of the class that accepts an array of instances of the class and does the extraction / deletion. See the remove method of the attached class for a basic example.

test1 = test735052(1,2,3,4);
test2 = test735052(1,3,5,7);
test3 = test735052(2,4,6,8);

all_tests = [test1,test2,test3]
all_tests2 = remove(all_tests, 20)

[Niklas Braun]

Thank you very much for your input. Do you have any suggestions on how I could optimize the minimum index search? 4 Lines of code and the Introduction of IDs feels rather complicated.