Hey guys, I am really lost and I don't know where to start with this question

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 array. Each struct should contain three fields with these (exact) field names: “month”, “date”, and “day” (all lower case).  The month field must contain a string with the name of the month (first letter capitalized).  The date field must contain a scalar specifying the day of the month.  The day field must contain the three-letter abbreviation of the day chosen from this list: 'Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'. For example, here is a call of the function followed by a command that shows the seventh element of the struct array that is returned by the function: >> m = year2016(2); >> m(7) ans = month: 'February' date: 7 day: 'Sun'

I have been trying for hourse. I am not sure how to make it so, that when i call the function afther that i have the option to write m again but this time give it a value and to become the day at the end. I would be really gratefull. It should look like this :

 m = year2016(4)
m = 
  1×30 struct array with fields:
    month
    date
    day
>> m(1)
ans = 
  struct with fields:

    month: 'April'
     date: 1
      day: 'Fri'

and myone one looks like this:

m = year2016(1)

m =

struct with fields:

    month: 'January'
      day: [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31]

Here is my code now, i have changed it more than 10 times so it doesnt really show my closest attempt probably, but would give some idea why i am not doing it right.

 function [m] = year2016( x )

 field1 = 'month'; field2 = 'date'; field3 = 'day';
 m1 = 'January';  m2 = 'February';  m3 = 'March';
 m4 = 'April';    m5 = 'May';       m6 = 'June'; 
 m7 = 'July';     m8 = 'Augustm';    m9 = 'September'; 
m10 = 'October'; m11 = 'November'; m12 = 'December';
d1 = {1,2,3}; d2 = [1:30]; d3 = [1;2;3];
m = struct(field1,m1,field2,d3);
%,m2,d1,m3,d3,m4,d2,m5,d3);
end

Answer 1

[Stephen23]

This code does the job (copied from my answer to this question, so this code is already in the public domain)

function out = year2016(m)
VN = datenum([2016,m,1]):datenum([2016,m+1,1])-1;
DN = 1+mod(VN-3,7);
MC = {'January';'February';'March';'April';'May';'June';'July';'August';'September';'October';'November';'December'};
DC = {'Mon','Tue','Wed','Thu','Fri','Sat','Sun'};
out = struct('day',DC(DN),'date',num2cell(1:numel(VN)));
[out(:).month] = deal(MC{m});
end

And tested:

>> m = year2016(12); m(8)
ans =
    day = Thu
    date =  8
    month = December
>> m = year2016(1); m(1)
ans =
    day = Fri
    date =  1
    month = January
>> m = year2016(2); m(29)
ans =
    day = Mon
    date =  29
    month = February
>> m = year2016(4); m(1)
ans =
    day = Fri
    date =  1
    month = April

[Stephen23]

Radoslav Gagov's "Answer" moved here:

Thank you :)

[Stephen23]

@Radoslav Gagov: my pleasure. Does it work for you, and help you to understand how to solve this task using MATLAB ?

Remember to you can accept the answer that best resolves your question. This is an easy way for you to thank all of us who volunteer on this forum.

[Radoslav Gagov]

Well it works, but i don't understand it completelly and i think they expect from us a code it in a bit lower lvl. Still trying to find out how to write it only with the knowledge I have so far.

[Stephen23]

It is quite simple, there are basically just four parts to it:

1. Generate a vector of serial date numbers for the chosen month
2. derive from that vector the days-of-the-week as a vector with values between 1 and 7.
3. use the day-of-the-week values and month value as indices and obtain the strings from the cell arrays.
4. generate the dates (day of the month) using a simple 1:numel(serial date numbers).

[Radoslav Gagov]

Hmmm.How do you know that DN = 1+mod(VN-3,7); is going to be the Daynumber.

I havent really used deal,num2cell and cell so much so its a bit harder to understand it. I think afther reading the explanations of all the fuctions i understood it almost except for the

[out(:).month] = deal(MC{m});

its like we crated a struct with the date and day but then combine it with a month or i dont know. Probably i need a little more experience to understand that, but still thank you.

[Stephen23]

"How do you know that DN = 1+mod(VN-3,7); is going to be the Daynumber?"

Trial-and-error. It is easy to find the serial date number for today (use the function now). Obviously we need mod 7 (because of seven days per week), and the offset can be figured out quickly with a few examples. The plus one is because I want to use this as an index, and MATLAB indices start from one (not zero).

"its like we created a struct with the date and day"

Exactly correct. The date and day make a structure with 28/29/30/31 elements. But notice that the month name is the same all month long! And note that MC{m} is just one month name. Therefore we want to allocate one month name to all 28/29/30/31 elements of the structure. This is exactly what

 [out(:).month] = deal(MC{m});

does. The LHS is all 28/29/30/31 elements of out in a comma-separated list, and the deal allocates our single month name to every member of that list (creating the month field too).

See my answer to this question which explains it a bit differently.

Answer 2

[Jose alberto Guzmán Torres]

Que pasa para cuando los valores de m se salen del intervalo de 1 a 12?? ¿Como solucionas eso?

[Stephen23]

Read the assignment again: "If the input is not an integer between 1 and 12, the function returns the empty array."

The answer is right there in the assignment: use IF.

The answer is also in the discussion here:

https://www.mathworks.com/matlabcentral/answers/342062-write-a-function-called-year2016-that-returns-a-row-vector-of-struct-s-whose-elements-correspond-to