[Octave-bug-tracker] [bug #65060] classdef: extremely slow writing to array properties

[A.R. Burgers]

URL:
  <https://savannah.gnu.org/bugs/?65060>

                 Summary: classdef: extremely slow writing to array properties
                   Group: GNU Octave
               Submitter: arb
               Submitted: Wed 20 Dec 2023 12:38:50 PM UTC
                Category: Interpreter
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Performance
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
                 Release: dev
         Discussion Lock: Any
        Operating System: Any
           Fixed Release: None
         Planned Release: None


    _______________________________________________________

Follow-up Comments:


-------------------------------------------------------
Date: Wed 20 Dec 2023 12:38:50 PM UTC By: A.R. Burgers <arb>
Assigning to array classdef properties can be painfully slow.
Consider this class:


classdef foo
  properties
    data_s = [];
    data_d = [];
  end
end


and this script to exercise the class:


nrep = 2000;
dims = [2000, 2, 20300];

fi = foo;
fi.data_s = zeros(dims, 'single');
fi.data_d = zeros(dims, 'double');
data_s = zeros(dims, 'single');
data_d = zeros(dims, 'single');

dat_set = rand(dims(1), dims(2));

tic;
for i = 1 : min(nrep, dims(3))
  data_d(:, :, i) = dat_set;
end
fprintf('Time for assign to double precision array: %g\n', toc);

tic;
for i = 1 : min(nrep, dims(3))
  data_s(:, :, i) = dat_set;
end
fprintf('Time for assign to single precision array: %g\n', toc);

tic;
for i = 1 : min(nrep, dims(3))
  foo.data_d(:, :, i) = dat_set;
end
fprintf('Time for assign to double precision property: %g\n', toc);

tic;
for i = 1 : min(nrep, dims(3))
  foo.data_s(:, :, i) = dat_set;
end
fprintf('Time for assign to single precision property: %g\n', toc);


octave 10 timings:


Time for assign to double precision array: 0.0131512
Time for assign to single precision array: 0.0130341
Time for assign to double precision property: 52.545
Time for assign to single precision property: 29.0633


matlab R2019b timings


Time for assign to double precision array: 0.036111
Time for assign to single precision array: 0.033317
Time for assign to double precision property: 0.012477
Time for assign to single precision property: 0.042348








    _______________________________________________________
File Attachments:


-------------------------------------------------------
Date: Wed 20 Dec 2023 12:38:50 PM UTC  Name: u_foo.m  Size: 772B   By: arb

<http://savannah.gnu.org/bugs/download.php?file_id=55468>
-------------------------------------------------------
Date: Wed 20 Dec 2023 12:38:50 PM UTC  Name: foo.m  Size: 70B   By: arb

<http://savannah.gnu.org/bugs/download.php?file_id=55469>

    _______________________________________________________

Reply to this item at:

  <https://savannah.gnu.org/bugs/?65060>

_______________________________________________
Message sent via Savannah
https://savannah.gnu.org/