[bug #48564] Octave does not accept "1 / ND array", "mrdivide (1, ND array)", "mldivide (ND array, 1)"

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Follow-up Comment #17, bug #48564 (group octave):

generally identical behavior for mldivide:


x = A\B solves the system of linear equations A*x = B. The matrices A and B
must have the same number of rows. MATLAB® displays a warning message if A is
badly scaled or nearly singular, but performs the calculation regardless.

If A is a scalar, then A\B is equivalent to A.\B.

If A is a square n-by-n matrix and B is a matrix with n rows, then x = A\B is
a solution to the equation A*x = B, if it exists.

If A is a rectangular m-by-n matrix with m ~= n, and B is a matrix with m
rows, then A\B returns a least-squares solution to the system of equations
A*x= B. x may not be the minimum-norm solution.




>> rand(1,3)\9

ans =

    9.5221
         0
         0

>> rand(3,1)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(2,2)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(2,4)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(4,2)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(3,3)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(3,3,3)\9

ans(:,:,1) =

   82.0438   20.0726   14.3336
  141.5286   24.6025   11.6583
   22.2453   11.7877    9.6478


ans(:,:,2) =

    9.2522   12.9261   16.9701
   46.8681   95.9283   10.4513
   64.8069   17.1297   18.5623


ans(:,:,3) =

   22.8742   17.3059   15.3559
   13.4042   25.8834   34.3321
   12.1415   60.0011  202.4561

>> rand(3,2,1)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(3,0,1)\9
Error using  \ 
Matrix dimensions must agree.
 
>> rand(3,0,2)\9

ans =

  3×0×2 empty double array

>> rand(3,2,0)\9

ans =

  3×2×0 empty double array

>> rand(3,1,0)\9

ans =

  3×1×0 empty double array



and in octave:


octave:16> rand(1,3)\9
ans =

   8.9070
   3.3178
   5.0056

octave:17> rand(2)\9
error: operator \: nonconformant arguments (op1 is 2x2, op2 is 1x1)
octave:18> rand(2,4)\9
error: operator \: nonconformant arguments (op1 is 2x4, op2 is 1x1)
octave:19> rand(4,2)\9
error: operator \: nonconformant arguments (op1 is 4x2, op2 is 1x1)
octave:20> rand(3)\9
error: operator \: nonconformant arguments (op1 is 3x3, op2 is 1x1)
octave:21> rand(3,3,3)\9
error: operator \: nonconformant arguments (op1 is 3x9, op2 is 1x1)
octave:22> rand(3,2,1)\9
error: operator \: nonconformant arguments (op1 is 3x2, op2 is 1x1)
octave:23> rand(3,0,1)\9
error: operator \: nonconformant arguments (op1 is 3x0, op2 is 1x1)
octave:24> rand(3,0,2)\9
error: operator \: nonconformant arguments (op1 is 3x0, op2 is 1x1)
octave:25> rand(3,2,0)\9
error: operator \: nonconformant arguments (op1 is 3x0, op2 is 1x1)
octave:26> rand(3,1,0)\9
error: operator \: nonconformant arguments (op1 is 3x0, op2 is 1x1)




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