Input cell to function

I have written a function which accepts as an input a cell array consisting of any number of strings. I have it structured as follows:

function grade_pt= gpa(varargin)

grades= {'a+','a', 'a-', 'b+', 'b', 'b-', 'c+', 'c', 'c-', 'd', 'f'};

eq_pt = {4, 4, 3.7, 3.3, 3, 2.7, 2.3, 2, 1.7, 1, 0};

res=zeros(nargin,length(grades));

grdvec=zeros(1,nargin)

for n = 1:nargin;

res(n,:)= strcmpi(varargin{n}, grades);

grdvec(n)=eq_pt{res(n,:)==1};

grade_pt=sum(grdvec)/nargin;

end

end

I call this function like this:

gpa('a+','b-','b')

calling 'whos' within the function reveals (as I designed it) that I have input 3 values in a 1x3 cell.

When I call the function as I did above, or with any number of input arguments, everything works fine. The function computes the gpa and returns a double value. It does this by comparing each grade with the vector of grades, finding a logical match, and the matching grade_pt. It then sums the results and divides by the number of inputs to get the gpa.

I also made a structure consisting of students' names, their courses and the grades that they earned in each course.

I extracted the letter grades and stored them in a cell array called 'grades' where each row corresponds to a student. Here's an excerpt from the code, it has just the last 'student' and the code to create the cell array, 'grades.'

student(7).name = 'Tobias Funke';

student(7).courses(1).course_name = 'PSYCH 620';

student(7).courses(1).grade = 'A';

name = cell(1,7);

grades =cell(7,6);

for n=1:7

    name{n} = student(n).name

for x = 1:length(student(n).courses)

   grades{n,x} = student(n).courses(x).grade

end end

I then called the function gpa(grades(n,:)).

This returns an error:

"Error using strcmpi Inputs must be the same size or either one can be a scalar.

Error in gpa (line 16) res(n,:)= strcmpi(varargin{n}, grades);"

calling 'whos' reveals (much to my chagrin) that I have input only ONE value. That value is a cell array.

My question:

How do I take the contents of the cell array 'grades' break it up so that I can input it into my function and it will read it as 3 values.

Or, how do I alter my function to break up the input into its constituent parts (making sure though that a 'b+' is still read as a single value)??

HELP!!!

Thanks for reading all of this, I know its long. Id really appreciate any input or advice. Am I making this too difficult? Is there a much simpler solution?

[Jan]

Please mark your code and press the "{} Code" button to improve the readability.

Answer 1

[Andrei Bobrov]

use

gpa(grades{n,:})

OR use new function gpanew.m :

function grade_pt= gpanew(incell)
    grades= {'a+','a', 'a-', 'b+', 'b', 'b-', 'c+', 'c', 'c-', 'd', 'f'};
    eq_pt = {4, 4, 3.7, 3.3, 3, 2.7, 2.3, 2, 1.7, 1, 0};
    grade_pt = mean(cell2mat(eq_pt(ismember(grades,lower(incell)))));
end

here incell - cell array -> gpanew({'B-','c+'}) as your gpa('B-','c+') then use

gpanew(grades(n,:))

Answer 2

[Stephen]

Nope. Doesn't work. That reads grades{n,:} into gpa as a single value. So, in the function, nargin = 1, when it should = between 4 and 6 depending on the student, or how many letter grades are stored in the cell.

How I got around it is

grades(cellfun('isempty',grades))=[];

then counted through to pull out the right letter grades and input based on indexing the new 'grades.'

[Jan]

Please post comments in the comment section and not as an answer. Thanks.