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## [Octave-bug-tracker] [bug #55751] Possible regression bug in Octave 5.0.

 From: Rick T Subject: [Octave-bug-tracker] [bug #55751] Possible regression bug in Octave 5.0.91 Date: Wed, 20 Feb 2019 16:23:54 -0500 (EST) User-agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/71.0.3578.98 Chrome/71.0.3578.98 Safari/537.36

```URL:
<https://savannah.gnu.org/bugs/?55751>

Summary: Possible regression bug in Octave 5.0.91
Project: GNU Octave
Submitted by: ratulloch
Submitted on: Wed 20 Feb 2019 09:23:52 PM UTC
Category: None
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Regression
Status: None
Assigned to: None
Originator Name:
Originator Email:
Open/Closed: Open
Discussion Lock: Any
Release: 5.0.91
Operating System: GNU/Linux

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Details:

Mike Miller said "... you've found a performance regression in Octave 5. Can
you file a bug report?"
The example to test the bug he gave is the one below.

[x, y, z] = peaks (32);
[x, y, z] = deal (x(:), y(:), z(:));
tic;
scatter3 (x, y, z);
toc
\$ octave-4.4.1 t.m
Elapsed time is 0.104946 seconds.
\$ octave-5.0.91 t.m
Elapsed time is 20.1961 seconds.

My example that had issues with plotting is below (it was never able to finish
the plot)

Octave code converted:
%%========================
%%2D Pseudo Quaterion Rotation Program in converted from Scilab 6.01 to Octave
5.0.91
w1=111
w2=333
w3=777
%% No phase differences in this: add in phi1 and phi2 phase differences if
desired to the psi and phi angles

n = [0:.001:45];
x1=50.*cos((n./360).*2.*pi.*w1).*(1.144.*n./100); %%w = mu cos theta, the
scalar
x2=50.*cos((n./360).*2.*pi.*w2).*(1.144.*n./100); %%cos phi
y1=50.*cos((n./360).*2.*pi.*w3).*(1.144.*n./100); %%cos psi
y2=50.*sin((n./360).*2.*pi.*w1).*(1.144.*n./100); %%sin theta
z1=50.*sin((n./360).*2.*pi.*w2).*(1.144.*n./100); %sin phi
z2=50.*sin((n./360).*2.*pi.*w3).*(1.144.*n./100); %%sin psi
x = y2.*x2;
y=y2.*z1.*y1;
z = y2.*z1.*z2;

scatter3 (x, y, z);  %color can be created based on z

xlabel('X-axis')
ylabel('Y-axis')
zlabel('Z-axis')
grid on

az = 347; %90;
el = 37; %180;
view([az,el]);

_______________________________________________________

<https://savannah.gnu.org/bugs/?55751>

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```