Grading system in excel sheet based on marks - excel

Question

I am trying to paste grades in excel sheet based on marks
i do this but this shows only F in excel sheet .. i want if anybody has marks >=80 then want to show A grade .. and if anybody hay >=70 then B
and if anybody have less than 70 then want to show F
UPDATED CODE
clc,clear all
filename = 'PROJECT..xlsx';
table = readtable(filename);
data = xlsread(filename);
[r,c] = size(data);
total_courses = c;
table.SumofMarks = zeros(r,1);
table.Percentage = zeros(r,1);
table.StudentGrade = repmat({''},r,1);
% Sum of marks in different courses and their percentage.
format bank
Sum_of_Marks = sum(data,2);
Student_Percentage = Sum_of_Marks./total_courses;
T = horzcat(Sum_of_Marks,Student_Percentage);
N = length(Student_Percentage);
table.SumofMarks = Sum_of_Marks;
table.Percentage = Student_Percentage;
for i = 1:63
sheet1=readtable(filename);
mark=sheet1{i,{'CALCULUS','DISCRETE','ECONOMICS','ISLAMIAT','STATISTICS'}};
if mark(mark<40)
grade='F';
sheet1(i,'StudentGrade')=cellstr(grade);
else
continue
end
end
writetable(table,filename)
xlswrite(filename,T,1, 'H2')
xlswrite(filename,grade,1,'J2')
these are the errors which I get
Error using getRowIndices (line 75)
Row index exceeds table dimensions.
Error in table/subsrefBraces (line 17)
[rowIndices,numRowIndices] =
getRowIndices(t, s(1).subs{1});
Error in table/subsref (line 60)
[varargout{1:nargout}] =
subsrefBraces(t,s);
Error in lab4 (line 38)
mark=sheet1{i,{'CALCULUS','DISCRETE','ECONOMICS','ISLAMIAT','STATISTICS'}};
i tried this but this code doesnt work
how i do this
i paste link where my file is located.. and I want if any student get less than 40 marks in any subject then want to show F grade.. this code shows if total marks is less than 40 .. where as I want to show if marks is less than 40 in any subject
this is the excel file
https://drive.google.com/file/d/1VQ8XxAQPu6reY0SCNV9Rxt65w1koduGA/view?usp=sharing

Answer 1

I don't have Excel installed, so I can't check the part about reading and writing to Excel, but you should replace
if R>=80
table.StudentGrade{i} = 'A';
elseif R>=70
table.StudentGrade{i} = 'B';
elseif R <70
table.StudentGrade{i}= 'F';
end
with
if R(i)>=80
table.StudentGrade{i} = 'A';
elseif R(i)>=70
table.StudentGrade{i} = 'B';
elseif R(i) <70
table.StudentGrade{i}= 'F';
end