How to take mean of the first numbers of column in matrix and add to each number in same column?

Hi guys I have a matrix:

A = [...
64     2     3    61    60     6     7    57
 9    55    54    12    13    51    50    16
17    47    46    20    21    43    42    24
40    26    27    37    36    30    31    33
32    34    35    29    28    38    39    25
41    23    22    44    45    19    18    48
49    15    14    52    53    11    10    56
 8    58    59     5     4    62    63     1]

Now I would like to take the mean of the first 4 numbers in column 1 and add to each number in column 1. In the second column I want to take the mean of the first 4 numbers and add to each number in column 2. And so on. Can this be done in a easy manner or do I have to import the data and calculate the mean myself and then add to the columns in the matrix? Help is greatly appreciated. Thx in advance.

Kind regards

A MatLab Novice

[Image Analyst]

Looks like homework - is it?

Answer 1

[Image Analyst]

This is how I do it (hope it's not your homework I just did):

A = [...
64     2     3    61    60     6     7    57
 9    55    54    12    13    51    50    16
17    47    46    20    21    43    42    24
40    26    27    37    36    30    31    33
32    34    35    29    28    38    39    25
41    23    22    44    45    19    18    48
49    15    14    52    53    11    10    56
 8    58    59     5     4    62    63     1]
meanOfRows1to4 = mean(A(1:4,:), 1)
rows = size(A, 1);
output = A + repmat(meanOfRows1to4, [rows, 1])

output =
         96.5         34.5         35.5         93.5         92.5         38.5         39.5         89.5
         41.5         87.5         86.5         44.5         45.5         83.5         82.5         48.5
         49.5         79.5         78.5         52.5         53.5         75.5         74.5         56.5
         72.5         58.5         59.5         69.5         68.5         62.5         63.5         65.5
         64.5         66.5         67.5         61.5         60.5         70.5         71.5         57.5
         73.5         55.5         54.5         76.5         77.5         51.5         50.5         80.5
         81.5         47.5         46.5         84.5         85.5         43.5         42.5         88.5
         40.5         90.5         91.5         37.5         36.5         94.5         95.5         33.5

[Thomas]

Thank you!

Haha, no. I am doing some signal processing from a force plate and I need to do an offset from the six channels so the measurement starts at zero, if that makes sense :-).

Answer 2

[Azzi Abdelmalek]

Edit

b=bsxfun(@plus,A,mean(A(1:4,:))')