how to load fisheriris data set by reducing the number of sample for each species

I am using fisheriris data set in my matlab code.

As fisheriris contain 3 species of 50 samples each.In total it contains 150 samples with 4 features.

Could anyone help me how to load 3 samples from 3 species inorder to make in total 9 samples containing 4 features.

[Rik]

I don't have the required toolbox, so this file is not available for me:

fullfile(matlabroot, 'toolbox', 'stats', 'statsdemos', 'fisheriris.mat')

But this looks like you should be able to load this file, and use the species variable to separate the different species.

Do you want to have a random selection of 3 of each species?

Answer 1

[KSSV]

load fisheriris.mat ;
str = unique(species) ;  
% pick any three randomly 
pos = zeros(3,3) ;
for i = 1:3
    idx = find(contains(species,str{i})) ;
    pos(:,i) = randsample(idx,3) ;
end
iwant = meas(pos(:),:)    

[jaah navi]

wheni run the code its showing error stating Undefined function 'contains' for input arguments of type 'cell'.

Error in fish (line 6)

idx = find(contains(species,str{i})) ;

[Walter Roberson]

Which release R2016a or earlier are you using?

[KSSV]

Use strcmp instead of contains

[jaah navi]

ok.It works and selects random of three samples out of 50 samples from each species.

Could you help me how to select first three samples out of 50 samples from each species.

[KSSV]

load fisheriris.mat ;
str = unique(species) ;  
% pick any three randomly 
pos = zeros(3,3) ;
for i = 1:3
    idx = find(strcmp(species,str{i})) ;
    pos(:,i) = idx(1:3) ;
end
iwant = meas(pos(:),:)    

jaah navi you have asked 97 questions so far.....by this time you should have learned basics of MATLAB. I advise you to read basic tutorials.

[Walter Roberson]

jaah navi indicates R2015a as the release.

[Adolfo Jaimes]

what does meas mean in matlab?

[Rik]

Nothing specific. It is simply one of the variables stored in this example data. It is probably short for measurement.