finding mean in row wise

I have values as

D=rand(3,7)

D =

    0.5407    0.3181    0.6456    0.5447    0.7210    0.2187    0.0636
    0.8699    0.1192    0.4795    0.6473    0.5225    0.1058    0.4046
    0.2648    0.9398    0.6393    0.5439    0.9937    0.1097    0.4484

i want to find mean of 3column,next 2 ,next 2

for example

3columns

    0.5407    0.3181    0.6456    
    0.8699    0.1192    0.4795  
    0.2648    0.9398    0.6393

now want to find mean in row wise ,so i will get

mean1 mean2 mean3

same way i have to do for others also

please help

Answer 1

[Pedro Villena]

 mean1 = mean(D(:,1:3),2),
 mean2 = mean(D(:,4:5),2),
 mean3 = mean(D(:,6:7),2),

or

 D1 = [37.8518   22.2652   45.1886   38.1301   50.4733   15.3074    4.4514;
     60.8959    8.3450   33.5624   45.3118   36.5747    7.4059   28.3206;
     18.5345   65.7881   44.7522   38.0720   69.5593    7.6788   31.3861];
 d = sort(D1,2);
 meanData = mean(d(:,1:(end+1)/2:end),2);

 meanData =
    4.4514   15.3074     22.2652   
   28.3206    7.4059      8.3450    
   31.3861    7.6788     65.7881

[Pat]

ok thanks Pedro another question suppose my data ia 

D1 =

     37.8518   22.2652   45.1886   38.1301   50.4733   15.3074    4.4514
     60.8959    8.3450   33.5624   45.3118   36.5747    7.4059   28.3206
     18.5345   65.7881   44.7522   38.0720   69.5593    7.6788   31.3861

in this i have to take first row,i have to choose 3 values,min max and middle value and find the mean with its nearesr values

4.4514   15.3074    22.2652   
28.3206   7.4059     8.3450    
31.3861  7.6788     65.7881 

for this i have to find mean in row wise ,

sane for next two ,and so on till end

Answer 2

[Walter Roberson]

mean(D(:,1:3),2)