Error using == function when trying to group certain data

Im trying to run a code to create a subset of a group i.e females who are credit worthy but im struggling with getting program to recognize f for females

>> worthyf = credit(credit.gender=='f' & credit.Risk_class==1,:);

Undefined operator '==' for input arguments of type 'cell'.

Answer 1

[Jesus Sanchez]

== only works for numbers. You are comparing strings and therefore you need to use "strcmp"

https://es.mathworks.com/help/matlab/ref/strcmp.html

An example in your code:

worthyf = credit(strcmp(credit.gender,'f') & credit.Risk_class==1,:);

[MZINGAYE MUBAYA]

Perfect Thank you so much for prompt response

[Guillaume]

== only works for numbers.

Not quite. It also works for single characters, and for categorical arrays, and for any class that overloads the == operator. Not that if x is a (scalar) categorical array.

if x == 'something'
    disp('it''s something');
elseif x == 'somethingelse'
    disp('it''s something else');
end

is perfectly valid. Try it with

x = categorical({'somethingelse'});

[Jesus Sanchez]

I did not know that. Thank you for the clarification and information :)

[Guillaume]

Actually, I completely forgot the most relevant class here, the newish string class. This has an overloaded == operator that is equivalent to strcmp. Unfortunately, that's going to lead to lot of confusion for beginner because indeed == doesn't work as they expect for char arrays (which unfortunately many people call strings) but does work for actual strings.

s = "somethingelse";   %an actual matlab string
if s == "something"
    disp('it''s something');
elseif s == "somethingelse"
    disp('it''something else');
end

works as expected

s = 'something else'
if  s == 'something'    %proper syntax: if strcmp(s, 'something')
    disp('it''s something');
elseif s == 'somethingelse'
    disp('it''something else');
end

does not work. you have to use strcmp. strcmp also works for actual strings, so it may be safer to always use that.

[MZINGAYE MUBAYA]

So basically use strcmp for my data set