Count number of distinct columns in a matrix
10613
Find unique rows in numpy.array
111501
Making sure length of matrix row is all the same (python3)
130531
SELECT DISTINCT on multiple columns
77908
How to count the number of occurrences of each item in an array?
57566
SQL to find the number of distinct values in a column
2628
Counting number of moves on a grid
70397
Building matrices by attaching vectors (columns) and matrices
31326
Number of $(0,1)$ $m\times n$ matrices with no empty rows or columns
3151
Elegant operations on matrix rows and columns
763
Horizontal enumeration in multiple columns
138610
How do I divide the columns of a matrix by the sum of its elements?
108071
Find unique columns and column membership
27582
How do I iterate through each element in an n-dimensional matrix in MATLAB?
52564
$m\times n$ matrix with an even number of 1s in each row and column
66842
Number of $n^2\times n^2$ permutation matrices with a 1 in each $n\times n$ subgrid
116251
Number of distinct total orders on a set
155819
Count the number of unique elements of a list of tuples regardless of order in Python