How to organize a new matrix like matrix B ?

If I have matrix A that contains 4 columns. like this

A = [7210 01/12/2016 00:15:00 0 0.5502;
     7210 01/12/2016 00:15:00 2 0.4903;
     7210 01/12/2016 00:30:00 0 0.5487;
     7210 01/12/2016 00:30:00 2 0.4914 ]

First column is a customer id and second column contains date time data.

I try to construct output matrix B to get the result follow this example

B = [7210 01/12/2016 00:15:00 0.5502 0.4903;
     7210 01/12/2016 00:30:00 0.5487 0.4914]

How can create program to get a result like matrix B ?

Thanks in advance.

Answer 1

[Matt J]

B=A([2,4],:)

[Pradya Panyainkaew]

Sorry Matt J .

I think it is my fault to explain my point deeply. The last 2 columns of result (Matrix B) show the value of flag "0" and flag "2" (column 3 of A) in each interval. However, your code create only a value of flag "2". How can I modify it to get my result ?

Answer 2

[Akira Agata]

Assuming your data A is stored in table format, I believe one possible solution would be like this.

% Your data stored in table format
ID = [7210; 7210; 7210; 7210];
Time = [...
  datetime('01/12/2016 00:15:00','InputFormat','dd/MM/yyyy HH:mm:ss');...
  datetime('01/12/2016 00:15:00','InputFormat','dd/MM/yyyy HH:mm:ss');...
  datetime('01/12/2016 00:30:00','InputFormat','dd/MM/yyyy HH:mm:ss');...
  datetime('01/12/2016 00:30:00','InputFormat','dd/MM/yyyy HH:mm:ss')];
Flag = [0;2;0;2];
Value = [0.5502;0.4903;0.5487;0.4914];
A = table(ID,Time,Flag,Value);

% Create the result B
A1 = A(A.Flag == 0,{'ID','Time','Value'});
A2 = A(A.Flag == 2,{'ID','Time','Value'});
B = innerjoin(A1,A2,'Keys',{'ID','Time'});

[Pradya Panyainkaew]

I try to run this code but the matlab software shows this error

" Undefined operator '==' for input arguments of type 'table'.

Error in Untitled2 (line 8)

A1 = A(eq(A.Flag,0),{'ID','Time','Value '});"

[Akira Agata]

What is your MATLAB version? At least on the latest one (R2017b), this code works.

[Pradya Panyainkaew]

Thanks sir. I got 2017a