2. Write a function called year2016 that returns a row-vector of struct-s whose elements correspond to the days of a month in 2016 as specified by the input argument. If the input is not an integer between 1 and 12, the function returns the empty arr

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Emma Sellers 2019-1-4

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评论： Emma Sellers 2019-1-4

采纳的回答： Jan

在 MATLAB Online 中打开

Please explain to me why this code will not work.

function[d] = year2016(m)

if m<1 || m>12 || ~isscalar(m)|| m~=fix(m)

d = [];

else days = datenum([2016,m,1]):datenum([2016,m+1,1])-1;

date = 1 + mod(days-3,7);

month = {'January', 'february','March', 'April', 'May', 'June', 'July','August', 'September','October', 'November', 'December'};

day = {'Mon', 'Tue', 'Wed','Thu', 'Fri','Sat'};

x = day(date);

y = num2cell(1:numel(days));

z = month(m);

d = struct('day',x, 'date',y,'month',z);

end

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Emma Sellers 2019-1-4

Problem 2 (year2016):

Feedback: Your function performed correctly for argument(s) 1

Feedback: Your function performed correctly for argument(s) 2

Feedback: Your function performed correctly for argument(s) 3

Feedback: Your function performed correctly for argument(s) 4

Feedback: Your function performed correctly for argument(s) 5

Feedback: Your function performed correctly for argument(s) 6

Feedback: Your function performed correctly for argument(s) 7

Feedback: Your function performed correctly for argument(s) 8

Feedback: Your function performed correctly for argument(s) 9

Feedback: Your function performed correctly for argument(s) 10

Feedback: Your function performed correctly for argument(s) 11

Feedback: Your function performed correctly for argument(s) 12

Feedback: Your function performed correctly for argument(s) 0

Feedback: Your function performed correctly for argument(s) -1

Feedback: Your function performed correctly for argument(s) 2.2

Feedback: Your program made an error for argument(s) [1 2]

Your solution is _not_ correct.

Emma Sellers 2019-1-4

The full question listed in the HW is posted above, underneath my code

Steven Lord 2019-1-4

在 MATLAB Online 中打开

In this case, order matters due to the short circuiting behavior of the || operator.

m = [1 2];

This section of code will error. The expression "m < 1" returns a vector not a scalar, and the || operator requires the two values with which it's computing to be scalar.

if m < 1 || ~isscalar(m)
    disp('wrong!')
end

This section of code will work and will display 'wrong!'. The expression "~isscalar(m)" returns true, which is a logical scalar value. Since "true or <something else>" is true, MATLAB doesn't need to evaluate the second part of the expression. Therefore the fact that "m < 1" would have returned a non-scalar when evaluated doesn't matter. It doesn't get that far.

if ~isscalar(m) || m < 1
    disp('wrong!')
end

If m were a scalar, "~isscalar(m)" would be false. Now MATLAB isn't sure whether the expression should be true or false based solely on the first expression's value, so it has to continue on to the second expression. But now we're guaranteed that "m < 1" returns a scalar which || can handle.

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