Unable to perform assignment because the left and right sides have a different number of elements. Error in Assignment​6ExcelCody​Madsen (line 44) letter(i) = 'B+' ; How do I fix this problem?

gradebook = xlsread('Exam_Grades_Data(1)');
display (gradebook);

%%Average Exam Grade for Each Student

% 0 - 59 = E
% 0 - 59 = E
% 0 - 59 = E
% 0 - 59 = E
% 0 - 59 = E

% loopend = length(x)
% loopend = length(grades)
i = 1:5;
average(i) = mean(gradebook(i,1:5));
temp = size(gradebook)
loopend = temp(1,1)

loopend = size(gradebook,1)

for i = 1:loopend
    average(i) = mean(gradebook(i,1:5));
end

for i = 1:loopend
    if (average(i) <= 59)
        letter(i) = 'E' ;
    elseif (average(i) <= 69)
        letter(i) = 'D' ;
    elseif (average(i) <= 75)
        letter(i) = 'C' ;
    elseif (average(i) <= 79)
        letter(i) = 'C+' ;
    elseif (average(i) <= 85)
        letter(i) = 'B' ;
    elseif (average(i) <= 89)
        letter(i) = 'B+' ;
    else
        letter(i) = 'A' ;
    end
end

display(Grades)
display(i)
display(average)
display(letter)

Answer 1

[Stephen23]

What you are doing will not work: (i) refers to one element of the char array letter, and it is not possible to force multiple characters into one element of a char array: one element is one character. You can use a cell array to store those char vectors:

C = cell(1,loopend); % preallocate cell array.
for k = 1:loopend
    if average(k) <= 59
        C{k} = 'E';
    ...  ^ ^ curly braces to access cell array contents
    end
end

Read more:

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-cell-array.html

Note that you don't need loops or switch for this task:

avg = mean(gradebook(:,1:5),2);
%avg = [0;23;45;67;89;100]; % test values
bin = [0, 60, 70, 75,  80, 85,  90, 100];
mrk = {'E','D','C','C+','B','B+','A'};
[~,idx] = histc(avg,bin);
idx = min(idx,numel(mrk));
out = mrk(idx)

Answer 2

[aqsa]

Unable to perform assignment because the size of the left side is 1-by-3377160 and the size of the right side is

1-by-3060288.plz help

[Walter Roberson]

We would need to see the code for this. I suggest you open a new Question for this.

[aqsa]

% Erxtecting Hog features for all training images and store in a vector

trainingFeatures= zeros(nImages,hogFeatureSize,'single');

for i=1: nImages

img=readimage(imdsTrain,i);

trainingFeatures(i,:)= extractHOGFeatures(img,'CellSize',CellSize);

end

trainingLabels=imdsTrain.Labels;

[Walter Roberson]

The number of hog features is different for different sizes of images.