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[Octave-bug-tracker] [bug #58366] [octave forge] (symbolic) equality ele
From: |
Nicholas Jankowski |
Subject: |
[Octave-bug-tracker] [bug #58366] [octave forge] (symbolic) equality element by element assignment produces Python exception |
Date: |
Wed, 13 May 2020 15:28:28 -0400 (EDT) |
User-agent: |
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.138 Safari/537.36 |
URL:
<https://savannah.gnu.org/bugs/?58366>
Summary: [octave forge] (symbolic) equality element by
element assignment produces Python exception
Project: GNU Octave
Submitted by: nrjank
Submitted on: Wed 13 May 2020 03:28:26 PM EDT
Category: Octave Forge Package
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Unexpected Error
Status: None
Assigned to: None
Originator Name: Nicholas Jankowski
Originator Email:
Open/Closed: Open
Release: 5.2.0
Discussion Lock: Any
Operating System: Any
_______________________________________________________
Details:
As first evidenced in a stackexchange post [1], making an element by element
assignment produces an error, apparently dependent on the assignment order.
here's a simpler example than at stackexchange that causes the same error:
runs fine in Matlab 2020a:
>> syms a b c d
>> e = [a == b, c == d]
e =
[ a == b, c == d]
>> f(1) = a==b
f =
a == b
>> f(2) = c==d
f =
[ a == b, c == d]
>> g(2) = c==d
g =
[ 0, c == d]
>> g(1) = a==b
g =
[ a == b, c == d]
>> h(2) = c==d
h =
[ 0, c == d]
>> h(1) = a==b
h =
[ a == b, c == d]
>> h(3) = a==c
h =
[ a == b, c == d, a == c]
output from Octave 5.2.0, Windows 10, with Symbolic 2.9.0 (and unbundled
Python 3.7):
>> pkg load symbolic
>> syms a b c d
Symbolic pkg v2.9.0: Python communication link active, SymPy v1.3.
>> e = [a == b, c == d]
e = (sym) [a = b c = d] (1x2 matrix)
>> f(1) = a==b
f = (sym) a = b
>> f(2) = c==d
error: Python exception: TypeError: cannot determine truth value of
Relational
occurred at line 7 of the Python code block:
if not A or not A.is_Matrix:
error: called from
pycall_sympy__ at line 178 column 7
mat_rclist_asgn at line 78 column 5
mat_replace at line 144 column 5
subsasgn at line 101 column 13
>> g(2) = c==d
g = (sym) [0 c = d] (1x2 matrix)
>> g(1) = a==b
g = (sym) [a = b c = d] (1x2 matrix)
>> h(2) = c==d
h = (sym) [0 c = d] (1x2 matrix)
>> h(1) = a==b
h = (sym) [a = b c = d] (1x2 matrix)
>> h(3) = a==c
h = (sym) [a = b c = d a = c] (1x3 matrix)
not sure what unique case is occurring under the hood when it goes from size
1->2, but the error doesn't reoccur at size 2->3.
_______________________________________________________
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<https://savannah.gnu.org/bugs/?58366>
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- [Octave-bug-tracker] [bug #58366] [octave forge] (symbolic) equality element by element assignment produces Python exception,
Nicholas Jankowski <=