Latest Date Entry Record

I have a large data set that contains multiple tests for the same pieces of equipment over many years. How can I isolate the latest test results only for the various pieces of equipment? There is a date stamp and equipment id and test results.

For example, for motor X, what are the last or current oil reports and ignore previous old test.

[KL]

how do you store your data?

[Faustino Quintanilla]

I have the information in a table. The table is updated daily with new test information.

Answer 1

[KL]

use sortrows,

https://de.mathworks.com/help/matlab/ref/sortrows.html#bt8bz9j-2

 sortedTable = sortrows(yourTable,'timestampColumnName')

[Faustino Quintanilla]

I was able to sorted them, but how do I isolate the last test for various equipment...

• Position_id Test Result Test Date
• -9999989 1 '2016-12-15 00:00:00.0000000'
• -9999989 1 '2014-12-08 00:00:00.0000000'
• -9999987 1 '2017-04-04 00:00:00.0000000'
• -9999987 1 '2016-11-16 00:00:00.0000000'Just need the last entry of 2016 or 2017 for the porsition_id.

[KL]

 T1 = sortrows(T(T.Position_id==x,:),'Time');

then T1(end) should have the latest value for the position_id x

[Faustino Quintanilla]

I tried the T1= sortrows(T(T.Position_id==x,:),'Time');... However, I t does not return the last entry.... DO I need to include a @max to single out? (not sure)

[KL]

The latest entry should be the last row of T1.

 T1(end,:)

[Faustino Quintanilla]

Here is the code used. Where do I add the T1(end,:)?

for x=1:height(sortedTable)
    T1 = sortrows(sortedTable(sortedTable.position_id==x,:),'sampledt_MAIN');
end

[KL]

Alright, you're extracting it for all equipments, so

 T_latest = table;
 for x=1:height(sortedTable)
    T1 = sortrows(sortedTable(sortedTable.position_id==x,:),'sampledt_MAIN');
    T_latest = [T_latest; T1(end,:)];
 end

now, T_latest should have the last entries corresponding to all x.

Answer 2

[Faustino Quintanilla]

I get an error... "Subscript indices must either be real positive integers or logicals." The intent is remove duplicate rows that have a older date stamp.. How to I correct the error?