Selecting Specific Elements in a Matrix Using Group

Hello, I am trying to select elements only from a single group from my data.

Let's say my current code is:

Height = [62; 65; 63; 70; 58; 70; 73]

Gender = [1; 1; 1; 2; 1; 2; 2] % where 1 is female and 2 is male

data_table = [Height(:), Gender(:)]

From the table, I would like to separate the male and female heights and put them into their own separate vectors so I can perform a two-sample t-test. Can anyone help me with this?

Thank you

Answer 1

[the cyclist]

Height = [62; 65; 63; 70; 58; 70; 73];
Gender = [1; 1; 1; 2; 1; 2; 2]; % where 1 is female and 2 is male
data_table = [Height(:), Gender(:)];

Height_F = Height(Gender==1)

Height_F = 4×1

62 65 63 58

Height_M = Height(Gender==2)

Height_M = 3×1

70 70 73

or

Height_F = data_table(data_table(:,2)==1,1)

Height_F = 4×1

62 65 63 58

Answer 2

[rumin diao]

you can use the function 'find' to locate different gender:

%current code
Height = [62; 65; 63; 70; 58; 70; 73];
Gender = [1; 1; 1; 2; 1; 2; 2]; % where 1 is female and 2 is male
data_table = [Height(:), Gender(:)];
%seperate female
female = find(Gender == 1);
heightOfFemale = Height(female);
male = find(Gender == 2);
heightOfMale = Height(male);

[the cyclist]

find is a waste of code here, because logical indexing will handle it (which is exactly what my solution did):

%current code
Height = [62; 65; 63; 70; 58; 70; 73];
Gender = [1; 1; 1; 2; 1; 2; 2]; % where 1 is female and 2 is male

%seperate female
female = (Gender == 1);
heightOfFemale = Height(female)

heightOfFemale = 4×1

62 65 63 58

male = (Gender == 2);
heightOfMale = Height(male)

heightOfMale = 3×1

70 70 73