Calculate Mean Score of subjects

Hi,

I need help with reading .txt files and calculate the mean score for subjects. There are four tests, we only want the average of test 1, test 3, and test 4 accross all four subject (1_1, 2_2, 3_3, 4_4). If the subject is absent for that specific test, we marked as '1', for example subject 1_1 is absent for 'test 4' 30 days ago.

If the subject is absent for 'test n' 30 days ago and 30 days after, we will not calculate the average score for this subject. However, if the subject is absent for 'test n' 30 days ago but present 30 days after, we will still calculate the average score for this subject.

Only 4 subject in this data set only, but we are expanding the numbers of data (expecting to be 1000 subjects)

Answer 1

[Seth Furman]

You can

1) find the mean across several variables using mean(t{:, ["Var1", "Var2", "Var3"]}, 2)

2) find rows that meet a certain condition (e.g. absent for both tests) by using logical indexing such as t{t.Condition1 & t.Condition2, "Mean"} = missing.

t = array2table(randi(10, 3, 4))

t = 3×4 table
    Var1    Var2    Var3    Var4
    ____    ____    ____    ____

     2        1      7       1  
     2        9      8       9  
     9       10      9       9  

t.Mean = mean(t{:, ["Var1", "Var2", "Var3"]}, 2)

t = 3×5 table
    Var1    Var2    Var3    Var4     Mean 
    ____    ____    ____    ____    ______

     2        1      7       1      3.3333
     2        9      8       9      6.3333
     9       10      9       9      9.3333

t{t.Var1 > 5 & t.Var2 > 5, "Mean"} = missing

t = 3×5 table
    Var1    Var2    Var3    Var4     Mean 
    ____    ____    ____    ____    ______

     2        1      7       1      3.3333
     2        9      8       9      6.3333
     9       10      9       9         NaN