if statement in for loop with cell arrays
显示 更早的评论
I have this problem with matlab, I have to assign letter grades to the scores I have, but I couldn't do it. Can anybody help?
s.name={'Seda','Ayça','Deniz','Kerem','Mete'}
s.score={'90','45','68','86','82'}
N=lenght(s.score)
for i = 1:1:N
if (i)<100 & (i)>=90
grades(i)='A'
elseif (i)<90 & (i)>=80
grades(i) ='B'
elseif (i)<80 & (i)>=70
grades ='C'
elseif (i)<70 & (i)>=60
grades ='D'
else
grades = 'F'
end
end
5 个评论
dpb
2019-10-29
You wrote the test on the variable i which isn't even defined in your code...
if (i)<100 & (i)>=90
...
You need to test the score for each element in the struct score field, but you could do so without a loop as well...unless using for...end is part of the assignment, of course.
Guillaume
2019-10-29
In addition, what is the purpose of the () brackets around i? They don't do anything at all, just make the code harder to read.
Note that the whole thing can be achieved in just one line by a call to discretize.
dpb
2019-10-29
Also, those would be prime candidates to be categorical ordinal variables instead of character if we're looking a niceties... :)
Fabio Freschi
2019-10-29
Can you have char varaible as values in discretize?
Can you have char varaible as values in discretize?
Yes,
>> score = [90, 45, 68, 86, 82];
>> discretize(score, [0 60 70 80 90 100], {'F', 'D', 'C', 'B', 'A'})
ans =
1×5 cell array
{'A'} {'F'} {'D'} {'B'} {'B'}
All discretize does is index the values array with the indices it would normally return. You can have pretty much anything that can be indexed as values.
回答（1 个）
Fabio Freschi
2019-10-29
To stick with the OP snippet
- I added semicolons all over the place
- I changed the variable type in s.score to doubles
- I preallocated the grades variable as string array
- I changed the check on (i) with s.score{i}
- I added <= 100 to include also the possibility of 100 score
- I changed the single & to double && for logical scalar values
s.name={'Seda','Ayça','Deniz','Kerem','Mete'};
s.score={90,45,68,86,82};
N=length(s.score);
grades = strings(N,1);
for i = 1:1:N
if s.score{i}<=100 && s.score{i}>=90
grades(i)='A';
elseif s.score{i}<90 && s.score{i}>=80
grades(i) ='B';
elseif s.score{i}<80 && s.score{i}>=70
grades(i) ='C';
elseif s.score{i}<70 && s.score{i}>=60
grades(i) ='D';
else
grades(i) = 'F';
end
end
类别
在 帮助中心 和 File Exchange 中查找有关 Matrix Indexing 的更多信息
2019-10-29
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
