How to plot a subset of x,y with group g according to fourth column

I have four columns in "data": day, bottle, species, finalC. I am trying to plot finalC as a function of day by group species, but I ONLY want to plot the bottles that are named "BETC". I cannot find anything to help me. I have tried this which doesn't work:

x = data.day

y = data.finalC

g = {data.bottle=="BETC", data.species}

gscatter(x,y,g)

Answer 1

[KSSV]

Let day, bottle, species, finalC be your data. I assume them to be columns and bottle is a cell array of strings.

% GEt indices of BETC
idx = contains(bottle,'BETC') ;   % if constains not available, use strcmp. 
scatter(day(idx),species(idx),10,finalC(idx),'filled')

[Clara Woodie]

Thank you for your reply. It did not work however. Bottle is a column in the data file and each row corresponds to an ID such as: BETC, BET, ETC, etc... I want to plot the data only when the rows of this column bottle say BETC. Do you have any more advice? Thanks.