Circshift bug for sparse logical.

Hello, does anybody know if it has been reported?

Circshift seems to shift sparse logicals properly, but changes trues to falses, which leads to several logical problems:

 >> C = circshift(sparse(true),1)

 C =

   (1,1)        0

 >> C == ~C

 ans =

   (1,1)        1

 >> C&C

 ans =

   (1,1)        0

 >> C|C

 ans =

   (1,1)        1

 % etc.

It's not a major problem since sparse logicals doesn't seem to be in common use and workaround with indexing is very simple. Bug confirmed in 2015a and 2015b, denied in 2010b, 2013a and 2013b. It probably exists since last changes in circshift in 2014a.

source

[Ray L]

2017b, the bug is still here

[DGM]

Welp, I guess that was changed somewhere between R2017b and R2019b. I didn't see anything in bug reports, but ... yeah.

C = circshift(sparse(true),1)

C = sparse logical
   (1,1)      1

C == ~C

ans = sparse logical
   All zero

C&C

ans = sparse logical
   (1,1)      1

C|C

ans = sparse logical
   (1,1)      1

[James Tursa]

Looks like bug is fixed, at least for this example (using sarek sparse matrix checker from FEX):

https://www.mathworks.com/matlabcentral/fileexchange/158161-sarek-sparse-analyzer-real-et-komplex?s_tid=srchtitle

>> st = sparse(true)
st =
sparse logical
(1,1)      1
>> sarek(st)

SAREK -- Sparse Analyzer Real Et Komplex , by James Tursa

Compiled in version R2020a (with -R2018a option)
Running  in version R2020a

Matrix is logical ...
    M = 1 >= 0 OK ...
    N = 1 >= 0 OK ...
    Nzmax = 1 >= 1 OK ...
    Jc[0] == 0 OK ...
    Jc[N] = 1 <= Nzmax = 1 OK ...
    Jc array OK ...
    Ir array OK ...
    All stored elements nonzero OK ...
    
All sparse integrity checks OK

ans =
0
>> 
>> cst = circshift(st,1)
cst =
sparse logical
(1,1)      1
>> sarek(cst)

SAREK -- Sparse Analyzer Real Et Komplex , by James Tursa

Compiled in version R2020a (with -R2018a option)
Running  in version R2020a

Matrix is logical ...
    M = 1 >= 0 OK ...
    N = 1 >= 0 OK ...
    Nzmax = 1 >= 1 OK ...
    Jc[0] == 0 OK ...
    Jc[N] = 1 <= Nzmax = 1 OK ...
    Jc array OK ...
    Ir array OK ...
    All stored elements nonzero OK ...
    
All sparse integrity checks OK

ans =
0

Answer 1

[Steven Lord]

This bug was fixed in release R2018a.