MATLAB: How to calculate the change in columns of one table and display it in another

Question

For example, I have a table:

User Date1 Date2 Date3 ….(I have 500+ dates)

{'A'} 1 6 10 …

{'B'} 2 8 11 …

{'C'} 3 9 14 …

{'D'} 4 11 11 …

I would like to create this table, showing the changes as each date progresses

User Date2 Date3 ….(I have 500+ dates)

{'A'} 5 4 …

{'B'} 6 3 …

{'C'} 6 5 …

{'D'} 7 0 …

Answer 1

You won't be able to do this with tables. Using Accessing Data in Tables, extract the data, take the diff along dimension 2, then build a new table from the results.

Date1 = [1:4]';
Date2 = [6 8 9 11]';
Date3 = [10 11 14 11]';
User = ["A" "B" "C" "D"]';
T = table(User,Date1,Date2,Date3)
T = 4x4 table
    User    Date1    Date2    Date3
    ____    _____    _____    _____

    "A"       1        6       10  
    "B"       2        8       11  
    "C"       3        9       14  
    "D"       4       11       11  
T2 = diff(T{:,2:end},[],2)
T2 = 4×2
     5     4
     6     3
     6     5
     7     0
●
T2 = table(T.User,T2);
T2=splitvars(T2);
T2.Properties.VariableNames = T.Properties.VariableNames([1,3:end])
T2 = 4x3 table
    User    Date2    Date3
    ____    _____    _____

    "A"       5        4  
    "B"       6        3  
    "C"       6        5  
    "D"       7        0