Center Columns

Problem

Center each column of data by subtracting its column mean, the effect of multiplying by the centering matrix.

Return the centered data as a list of rows of floats.

Hint

Every centered column sums to zero.

case 1

in: [[[1,2],[3,4],[5,6]]]

expected: [[-2,-2],[0,0],[2,2]]

case 2

in: [[[1,2],[2,4]]]

expected: [[-0.5,-1],[0.5,1]]

case 3

in: [[[5,5],[5,5]]]

expected: [[0,0],[0,0]]

case 4

in: [[[1,3,5]]]

expected: [[0,0,0]]

Starter codePython

def center_columns(data):
    # Your code here
    pass

4 test cases · run your code against them in the editor