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[Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it
From: |
Rik |
Subject: |
[Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it |
Date: |
Fri, 22 Jan 2021 12:47:18 -0500 (EST) |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.66 Safari/537.36 |
Follow-up Comment #12, bug #59850 (project octave):
There already will be some difference between the regular algorithm and the
"ByRows" algorithm. Also, I would note that we don't have freedom to innovate
here. Matlab has defined how "uniquetol" should behave. In particular, the
criteria deciding for rows is
all(abs(u-v) <= tol*max(abs(A),[],1))
The part after "tol" can be overridden by specifying the "DataScale" option.
I wonder if judicious choices about the tolerance and DataScale options will
do what you want.
Representing a point in an N-dimensional vector space as a row vector [x1, x2,
..., xN] then the Matlab criterion above says that a vector is nearly
identical if for each separate component (x1 - y1, x2 - y2, ...) the absolute
difference is less than some value.
That seems to work reasonably well. Take an example in 2-D
x = [0, 1];
y = [0, -1];
norm (x) == norm (y) == 1
So, these two vectors look somewhat the same, BUT
abs (1 - (-1)) == 2 will show that there are unique components and so the
vectors themselves are unique.
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- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, (continued)
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/17
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/17
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/18
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/18
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/21
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/21
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Rik, 2021/01/21
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/22
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/22
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/22
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it,
Rik <=
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Rik, 2021/01/22
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Markus Mützel, 2021/01/23
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/24
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Rik, 2021/01/24
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/25
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Rik, 2021/01/25
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/25
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, Rik, 2021/01/25
- [Octave-bug-tracker] [bug #59850] uniquetol missing, so I implemented it, anonymous, 2021/01/25