how to get the mean for specific rows number of one columns

1 5

2 7

3 9

1 9

2 7

3 9

if column 1 is month how to get the mean of January only which is 5 and 9 then feb which is 7 and 7 mean then march 9 and 9 mean

Thanks in advance

Answer 1

[Paul Hoffrichter]

M = [ ...
   1  5
   2  7
   3  9
   1  9
   2  7
   3  9
   ];

T = array2table( M, ...
   'VariableNames',{'Month','Rainfall'});
disp('Table');
disp(T)
Tmean = varfun(@mean,T,'InputVariables','Rainfall',...
   'GroupingVariables','Month');
disp('Mean of Rainfall by Month')
disp(Tmean)

Output

Table
    Month    Rainfall
    _____    ________
      1         5    
      2         7    
      3         9    
      1         9    
      2         7    
      3         9    
Mean of Rainfall by Month
    Month    GroupCount    mean_Rainfall
    _____    __________    _____________
      1          2               7      
      2          2               7      
      3          2               9     

[Hazem Mahmoud]

Thank you Paul. perfect discription of variables

[Paul Hoffrichter]

You're very welcom, Hazem.

[Hazem Mahmoud]

I am trying to plot them x,y

plot(Tmean(:,1),Tmean(:,3),'b-') is not working

please advice

[Paul Hoffrichter]

Is this what you want?

plot(Tmean.Month, Tmean.mean_Rainfall, '-bo')

[Hazem Mahmoud]

Yes, Sir. It worked :)

Thank you so much