Matlab Date Sorting Program, need help
aPexDrifta
NY
Hello, I'm currently trying to write a program which sorts birth dates imported from a text file, in descending order. The data is imported into a matrix of 100 rows and 3 columns; column 1 being the year(yyyy), column 2 being the month(mm), and column 3 being the day(dd). I am able to sort any of the 3 and reference the location of each element so I can swap the rows of each column, but I'm unable to figure out the problem of also sorting the other two columns without screwing up the order of the first. My main issue is that once I get the Year column sorted, the Month and Day columns follow their location just fine, but on elements of the same year, the month and day order are not in proper descending order.
Ex:
Year Month Day
2006 02 05
2006 02 11
2002 05 19
2000 02 18
2000 12 25
2000 10 12
etc...
Ex:
Year Month Day
2006 02 05
2006 02 11
2002 05 19
2000 02 18
2000 12 25
2000 10 12
etc...
0
Comments
function [y] = DateSort(x) % function definition line % H1: Sorts a vector into descending order using a BubbleSort % Input Arguments: % x = vector % Output Arguments: % y = vector x sorted in descending order n = length(x); % compute the number of elements in x sorted = 0; % a flag varaible used to determine if the vector is fully % sorted. sorted = 0 if not fully sorted, = 1 if fully sorted. passes = 0; % 0 passes completed at the start % while loop that continues to make passes through x until it is fully % sorted. while (~sorted) sorted = 1; % Assumes x is fully sorted at the start of each pass passes = passes + 1; % Add one to the number of passes % On each pass through vector x the for loop starts with the first % element and continues until the (n-passes) element. After the first % pass the smallest value in x will fall to the last element therefore % on the second pass there is no need to check to see if the last value % is in the correct order. After each subsequent pass the x(n-passes:n) % elements are in the correct order. This is why the for loop limits go % from 1 to (n-passes). for j = 1:n-passes if x(j) < x(j+1); % Compares the current element x(j) with the next % element x(j+1). temp = x(j); % Stores the current element in a temp memory location. x(j) = x(j+1); % Stores the next value into the current value. x(j+1) = temp; % Stores the original current value into the % next value. sorted = 0; % Sets sorted to 0 to indicate that an out of order % element was found. This will cause the while loop % to make another pass through x. end end end y = x; % returns the sorted vectorAs for the code, I don't really have much saved at the moment, it's mostly been trial and error in the command window.
% load function used to import data from a text file BDayData = load('Data_11_2.txt'); % Extracts the data from each column of BDayData YearData = BDayData(:,1); MonthData = BDayData(:,2); DayData = BDayData(:,3);>> [SortedData,OrigRows]=sort(BDayData(:,1),1,'descend'); >> BDayMat=BDayData(OrigRows,:) BDayMat = 2006 2 5 2006 2 11 2002 5 19 2000 2 18 2000 12 25 2000 10 12 1998 2 3 1996 11 13 1996 7 12 1996 6 2 1995 7 29 1993 1 18 1993 3 21 1991 11 5 1990 2 14 1990 6 14 1989 4 13 1989 8 14 1989 4 14 1989 7 23 1988 6 11 1988 2 8 1987 8 13 1987 11 21 1987 9 15 1987 8 31 1987 3 16 1986 7 2 1986 7 7 1985 2 8 1985 7 7 1985 11 23 1985 7 23 1984 11 13 1984 11 24 1984 5 29 1984 5 17 1984 7 23 1984 3 12 1984 7 30 1984 4 15 1983 6 11 1983 3 4 1983 11 25 1982 8 31 1982 4 2 1982 11 18 1982 8 12 1982 6 12 1981 10 28 1981 5 13 1981 6 25 1981 11 12 1981 9 29 1980 5 11 1980 12 11 1980 6 26 1980 5 25 1979 7 2 1979 11 6 1978 11 24 1978 4 18 1978 9 29 1978 7 15 1978 6 25 1977 11 26 1975 1 27 1975 9 14 1974 9 28 1974 1 14 1974 4 28 1974 4 1 1974 10 8 1974 9 30 1973 9 18 1973 4 20 1973 6 19 1973 1 9 1973 5 17 1972 10 12 1972 11 26 1972 8 31 1971 12 8 1971 6 29 1970 10 9 1970 4 7 1970 5 18 1970 4 4 1968 6 1 1968 3 14 1966 6 3 1965 7 16 1965 5 23 1964 3 9 1964 9 4 1961 5 13 1960 1 30 1959 4 25 1959 1 10 1957 2 27 >>So yeah, I'm pretty much stuck on trying to keep the year column in the same order, while just re-sorting the months and days within each section of years.
Here is my function: age
function [AgeVector] = age(BirthDates,year,month,day) % function definition % H1: Determines the age for birth dates given the current year,month,day % Input Arguments: % BirthDates = matrix of birth dates with the following columns: 4 digit % year, 2 digit month, 2 digit day % year is the current year % month is the current month % day is the current day % Output Arguments: % AgeVector = an integer vector that contains the age for each birth date % Memory has been preallocated for AgeVector, to increase speed AgeVector = zeros; % A for loop is used to fill the values of AgeVector [COLOR="Blue"]for[/COLOR] n=1:1:size(BirthDates,1) % an if-elseif construct is used to determine whether the current month % or day is less than that of the BirthDates matrix. [COLOR="blue"]if[/COLOR] (month < BirthDates(:,2)) % Subtracts one to account for that date having not yet passed AgeVector(n) = ((year-BirthDates(:,1))-1); [COLOR="blue"]elseif[/COLOR] ((month == BirthDates(:,2)) && (day < BirthDates(:,3))) AgeVector(n) = ((year-BirthDates(:,1))-1); [COLOR="blue"]else[/COLOR] AgeVector(n) = year - BirthDates(:,1); [COLOR="blue"]end[/COLOR] [COLOR="blue"]end[/COLOR]Some of the code from my program:
% Asks the user to input values for the year, month, and day Year = input('Please enter the current 4 digit year (yyyy) : '); Month = input('Please enter the current 2 digit month (mm) : '); Day = input('Please enter the current 2 digit day (dd) : '); % load function used to import data from a text file BDayData = load('Data_11_2.txt'); % The datenum function is used to change the dates listed into the date % number associated with them. This will allow us to easily sort the dates. TempData = datenum(BDayData); % The DateSort() function is used to sort the date numbers in ascending % order. SortedData = DateSort(TempData); % The datevec function outputs the values from the sorted data in vector % form. [SortedYears,SortedMonths,SortedDays] = datevec(SortedData); % The three sorted vectors are appended together to create a sorted matrix SortedDates = [SortedYears, SortedMonths, SortedDays]; % The age() function is used to compute the age based on the birthdate and % current date entered. Ages = age(SortedDates,Year,Month,Day)And the error I receive after I run:
Please enter the current 4 digit year (yyyy) : 2010 Please enter the current 2 digit month (mm) : 04 Please enter the current 2 digit day (dd) : 27 [COLOR="Red"]??? Operands to the || and && operators must be convertible to logical scalar values. Error in ==> age at 23 elseif ((month == BirthDates(:,2)) && (day < BirthDates(:,3))) Error in ==> Program_11_2 at 50 Ages = age(SortedDates,Year,Month,Day)[/COLOR] >>Once again, any feedback is appreciated,
you're looping over the length of birthdates with the variable n, but you're not using n to index either BirthDates(:,2) or Birthdates(:,3). you might want them to be BirthDates(n,2) and 3.
If that's not the issue, i'll take a closer look.