Get the first row in a table with grouped data

Hi everyone, I want to know if there is a function which can get me a table with the first row that appears in grouped data. For example, I have this table:

    key    Date    Height    Weight
    ___    ____    ______    ______

      4     56       34        12  
     21     45      123        23  
     21     40       67       133  
     45     49       64       119  
     45     45       12        12  

The column date is already grouped in descending order.

I want to get a table with unique values for key but with the most recent date like this.

    key    Date    Height    Weight
    ___    ____    ______    ______

      4     56       34        12  
     21     45      123        23  
     45     49       64       119  

Please help

Answer 1

[dpb]

[~,ig]=findgroups(D.key);
[~,ig]=ismember(ig,D.key);

results in:

>> D(ig,:)
ans =
  3×4 table
    key    Date    Height    Weight
    ___    ____    ______    ______
     4     56       34        12   
    21     45      123        23   
    45     49       64       119   
>> 

[Emmanuel Valadez Aguilar]

It works perfectly, Thanks!

[Namrata Goswami]

How to get the last row per group in a similar situation ?

[dpb]

You could either sort by the column of interest descending or use find() with the reverse search instead of ismember with a loop construct.