Definition of fiter in data by text in colomn

hello,

I would like to ask you for advice on the filter. I need to define a basic filter.

Filter all rows labeled "P1" in column 4.

data file contain more than mil rows with P1-P20 values

I tried

Data_P1=Data(Data(:,4)=="P1",:)

but it's bad

thank you

[KSSV]

@Marek Drliciak you are supposed to accept the answer which I have shown.

Answer 1

[KSSV]

idx = strcmp(Data.(4),'P1') ; 
T1 = T(idx,:) ; 

[Marek Drliciak]

Now it is ok.

Your advice was useful.

Sorry