How to make a function that tell us about grades using Matlab

Hi every one; I going to make a function called letter_grade that takes a positive integer called score as its input argument and returns a letter grade according to the following scale: A: 91 and above; B: 81-90; C: 71-80; D: 61-70; F: below 61. Remember that to assign a letter to a variable, you need to put it in single quotes, as in: grade = 'A'. when i run the below codes i got grade 'B' for score 95.which in not correct.Kindly guide me how can i correct this code. Please vote up if this question help!

function grade=letter_grade(n)
if n >= 91 && n>=100
   grade='A';
elseif n >= 81 && n>=90
  grade='B';
    elseif n >= 71 && n>=80
   grade='C';
    elseif n >= 61 && n>=70
  grade='D';
    elseif n <61 
   grade='F';
end
end

[Murali Krishna]

Grade B is defined when n is between 81 and 90 both inclusive. if n>81 and n<=90 grade should be B. But in your code you have written the condition as n>=81 and n>=90. The same error is for finding other grades.

[Jan]

@Goshom Brian and Qahar Mustafa: Please do not use flags to post comments. Thanks.

Answer 1

[Image Analyst]

Try it this way:

function grade=letter_grade(n)
if n >= 91
  grade='A';
elseif n >= 81
  grade='B';
elseif n >= 71
  grade='C';
elseif n >= 61
  grade='D';
else
  grade='F';
end
end

[Manoj]

how to display the names and roll numbers according to the Grades ?

[Image Analyst]

Try ismember() to get a list of all people that have a certain grade, then use fprintf() or celldisp() to display those people and roll numbers with that grade letter.

[Muhammad Aamir Hayat]

Hi there, can you please create the same program by using switch statement?

[Image Analyst]

@Muhammad Aamir Hayat, did you try it yourself first? I imagine you did. Did you get something like this:

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables. Or clearvars if you want.
workspace;  % Make sure the workspace panel is showing.
format long g;
format compact;

for n = 55:10:95
	grade=letter_grade(n);
	fprintf('A score of %d is an "%s".\n', n, grade);
end
fprintf('Done!  Thanks Image Analyst!\n');

%=========================================================================
function grade=letter_grade(n)
n2 = floor( (n-1) / 10);
switch n2
	case {9, 10}
		grade='A';
	case 8
		grade='B';
	case 7
		grade='C';
	case 6
		grade='D';
	otherwise
		grade='F';
end
end

A score of 55 is an "F".

A score of 65 is an "D".

A score of 75 is an "C".

A score of 85 is an "B".

A score of 95 is an "A".

Done! Thanks Image Analyst!

Answer 2

[SY]

What's the meaning of this program?

function [Average, StandardDeviation ] = F1_91(Scores)
% Prompt user to input grades(scores)
   Scores = input('Enter Grades: ');
 
%Calculating average of grades
 
  X = mean(Scores)
  
     
 
% Rounding off to nearest integer
 Average = round(X)
 
    
 
% Calculating standard deviation of grades
 
 SDD = std(Scores)
 
 
 
% Rounding off to nearest integer
    StandardDeviation = round(SDD)
     
end

[Image Analyst]

It simply computes the rounded standard deviation of a set of rounded numbers. Not sure what you mean by "meaning"? It's probably someone's homework answer.

[Walter Roberson]

It is someone's wrong homework answer at that. It should not pass in Scores and then overwrite Scores with the input()