Cell array indexing question

Question

Brittany Isbister 2021-2-20

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/751139-cell-array-indexing-question

回答： Stephen23 2021-2-22

采纳的回答： Stephen23

QuizGrades.mat

在 MATLAB Online 中打开

Hi All,

I'm trying to have it so that this will loop thorugh and put all the numbers/ characters in for the different places in the fprintf statement. I have it so it will run the name, but after that it won't run the right thing. Any help would be appreciated!

%% Part A
load('QuizGrades.mat')
student_Names={'Student1','Student2','Student3','Student4','Student5','Student6','Student7','Student8','Student9','Student10','Student11','Student12','Student13','Student14'};
student_IDs=[101:114];
grade_Book={student_Names,student_IDs,grades}
cellplot(grade_Book)
%% Part B
mean(grade_Book{3}(3,:))% mean of the quiz grades for student 3
mean(grade_Book{3}(:,5))% mean of student grades on quiz 5
mean(grade_Book{3}())% mean of grades for all quizzes
%% Part C
[M,I]=min(grade_Book{3},[],2)%minimum grade for each student in one vector and the index for the quiz in another
%% Part D
for x=[1:14]
    fprintf('<%s>(%d)will drop grade(%s)from grade(%s)',(grade_Book{1}{:}),(grade_Book{2}(:)),(grade_Book{3}{:}),I)
end

I'm trying to have it to say <student name> (student ID) will drop (grade) from quiz (indexed quiz number)

Thank you for your help in advance!

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Stephen23 2021-2-20

Please upload 'QuizGrades.mat' by clicking the paperclip button.

Brittany Isbister 2021-2-21

Hi Stephen,

The 'QuizGrades.mat' is uploaded for you!

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Answer 1

Stephen23 2021-2-22

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/751139-cell-array-indexing-question#answer_629834

在 MATLAB Online 中打开

QuizGrades.mat

%% Part A
S = load('QuizGrades.mat');
grades = S.grades
grades = 14×7
    78    88    56    67    85    96    63
    45    98    42    79    55    61    74
    56    80    45    83    70    51    44
    73    42    90    86    82    55    43
    98    91    82    56    94    77    72
    98    96    59    81    98    68    87
    49    81    97    79    73    61    96
    99    86    42    49    48    90    47
    98    85    66    47    49    75    74
    69    63    63    70    55    73    68
student_Names = "Student"+(1:14)
student_Names = 1×14 string array
    "Student1"    "Student2"    "Student3"    "Student4"    "Student5"    "Student6"    "Student7"    "Student8"    "Student9"    "Student10"    "Student11"    "Student12"    "Student13"    "Student14"
student_IDs = 101:114;
%% Part B
mean(grades(3,:))% mean of the quiz grades for student 3
ans = 61.2857
mean(grades(:,5))% mean of student grades on quiz 5
ans = 71.2857
mean(grades)% mean of grades for all quizzes
ans = 1×7
   75.6429   75.9286   66.8571   70.2143   71.2857   73.5714   64.6429
%% Part C
[M,I] = min(grades,[],2); %minimum grade for each student in one vector and the index for the quiz in another
%% Part D
fmt = '<%s>(%d)will drop grade(%d)from quiz(%d)\n';
for k = 1:14
    fprintf(fmt,student_Names(k),student_IDs(k),M(k),I(k))
end
<Student1>(101)will drop grade(56)from quiz(3)
<Student2>(102)will drop grade(42)from quiz(3)
<Student3>(103)will drop grade(44)from quiz(7)
<Student4>(104)will drop grade(42)from quiz(2)
<Student5>(105)will drop grade(56)from quiz(4)
<Student6>(106)will drop grade(59)from quiz(3)
<Student7>(107)will drop grade(49)from quiz(1)
<Student8>(108)will drop grade(42)from quiz(3)
<Student9>(109)will drop grade(47)from quiz(4)
<Student10>(110)will drop grade(55)from quiz(5)
<Student11>(111)will drop grade(40)from quiz(7)
<Student12>(112)will drop grade(48)from quiz(1)
<Student13>(113)will drop grade(49)from quiz(7)
<Student14>(114)will drop grade(41)from quiz(2)

Or avoiding the loop:

tmp = [cellstr(student_Names);num2cell([student_IDs(:),M,I]).'];
fprintf(fmt,tmp{:})
<Student1>(101)will drop grade(56)from quiz(3)
<Student2>(102)will drop grade(42)from quiz(3)
<Student3>(103)will drop grade(44)from quiz(7)
<Student4>(104)will drop grade(42)from quiz(2)
<Student5>(105)will drop grade(56)from quiz(4)
<Student6>(106)will drop grade(59)from quiz(3)
<Student7>(107)will drop grade(49)from quiz(1)
<Student8>(108)will drop grade(42)from quiz(3)
<Student9>(109)will drop grade(47)from quiz(4)
<Student10>(110)will drop grade(55)from quiz(5)
<Student11>(111)will drop grade(40)from quiz(7)
<Student12>(112)will drop grade(48)from quiz(1)
<Student13>(113)will drop grade(49)from quiz(7)
<Student14>(114)will drop grade(41)from quiz(2)