Searching for a value in struct array

Question

I am having a large struct array with following fields:

x
y
z_value
level

and I need to perform a search based on the condition like z_value == 10 && level = 5.

Currently my code loops from the first element to the last checking all the struct values. Since the array is large its taking ~80secs to complete.

Is there any other alternative(other than by using binary search,heap etc) to make this fast by exploiting in build features of matlab??

Answer 1

Assuming the struct to have only double data, this code would get all those indices where the mentioned condition is satisfied -

names = fieldnames(s1) %%//s1 is your input struct

%%// matdata = cell2mat(squeeze(struct2cell(s1)))' %%//' Approach -1
matdata = reshape(struct2array(s1),numel(names),[])' %%//' Approach -2
data1 = matdata(:,[find(strcmp(names,'z_value')) find(strcmp(names,'level'))])
index = find(ismember(data1,[10 5],'rows')) %%// indices where condition is met