Converting columns in a matrix to percentage

Hi there,

I have a data file that I would like to convert to percentage. It looks like this and is called nMJO.

48 40 35 52 38 11 64 39 26

50 35 37 55 43 24 54 25 26

33 27 36 28 26 27 39 27 16

40 29 40 51 29 24 47 32 29

66 37 38 51 41 16 52 29 24

62 41 37 48 40 17 41 23 24

57 26 33 46 29 8 37 21 24

63 39 22 47 45 11 38 25 17

I would like to convert each column to equal 100% and then for each value in every column, work out its percentage for that column. I would preferablly like to do this in a loop, and create a new matrix of percentages, that I can then plot as a stacked bar plots.

the code I've come up for so far is.

for i=1:9
    MJO_sum = sum(nMJO == i)
    for MJO_node_ind = 1:8
        nMJO_percent(MJO_node_ind, i) = nMJO/MJO_sum(:,i)
    end 
end 

Answer 1

[Stephen23]

>> M = [48,40,35,52,38,11,64,39,26;50,35,37,55,43,24,54,25,26;33,27,36,28,26,27,39,27,16;40,29,40,51,29,24,47,32,29;66,37,38,51,41,16,52,29,24;62,41,37,48,40,17,41,23,24;57,26,33,46,29,8,37,21,24;63,39,22,47,45,11,38,25,17]
M =
    48    40    35    52    38    11    64    39    26
    50    35    37    55    43    24    54    25    26
    33    27    36    28    26    27    39    27    16
    40    29    40    51    29    24    47    32    29
    66    37    38    51    41    16    52    29    24
    62    41    37    48    40    17    41    23    24
    57    26    33    46    29     8    37    21    24
    63    39    22    47    45    11    38    25    17
>> P = 100*bsxfun(@rdivide,M,sum(M,1))
P =
   11.4558   14.5985   12.5899   13.7566   13.0584    7.9710   17.2043   17.6471   13.9785
   11.9332   12.7737   13.3094   14.5503   14.7766   17.3913   14.5161   11.3122   13.9785
    7.8759    9.8540   12.9496    7.4074    8.9347   19.5652   10.4839   12.2172    8.6022
    9.5465   10.5839   14.3885   13.4921    9.9656   17.3913   12.6344   14.4796   15.5914
   15.7518   13.5036   13.6691   13.4921   14.0893   11.5942   13.9785   13.1222   12.9032
   14.7971   14.9635   13.3094   12.6984   13.7457   12.3188   11.0215   10.4072   12.9032
   13.6038    9.4891   11.8705   12.1693    9.9656    5.7971    9.9462    9.5023   12.9032
   15.0358   14.2336    7.9137   12.4339   15.4639    7.9710   10.2151   11.3122    9.1398

[Sophie Stringer]

Thanks a lot! that worked.

Cheers