How to extract rows from a table based on the categories present in one of the columns?

I have created a table that has double and categorical columns.How can I extract the rows that correspond to each one of the categories?

Being more specific, the table is called 'Plate' and one of the columns 'Invivo'.

If I write

categories(Plate.Invivo);

The answer gives me three categories

'Drug'

'Positive control'

'mock'

If I write

b=Plate(Plate.Invivo=='Drug',:);

The answer is a table with 0 rows and the same number of columns as the original table. Why it can not find the rows that correspond with the categorie 'Drug'?

Thanks a lot for your help

[madhan ravi]

Mind sharing the table?

[Ildefonso Vicente Suarez]

Please find attached to this comment the table I was talking about . Thanks a lot for your help!

Answer 1

[Esperanza Linares Guerrero]

The reason why you are getting an empty array, is because your category is not Drugs, it is 'Drugs' (between quotes). You can remove the quotes from the table and the command would work, or, you can define a variable that contains the quotes:

a=Plate.Invivo(end);%%% Checking your table, the last row has the 'Drugs' category
b=Plate.Invivo(Plate.Invivo==a,:)

[Ildefonso Vicente Suarez]

Thank you!. That worked

[Esperanza Linares Guerrero]

Alternatively use:

b=Plate.Invivo(Plate.Invivo=='''Drug''',:)

Answer 2

[KSSV]

b=Plate(strcmp(Plate.Invivo,'Drug'),:);

[Ildefonso Vicente Suarez]

Thanks a lot for answering my question. When I used your line of code the answer is a table with 0 rows.

I am attaching the table to this comment.