how to use box plot

hi, i have a mat file(5287*2) first column is date and time(with interval of 3 hours for years 2012 to 2015).and second column is my data (Hg concentration). i have been asked to use box plot and whiskers menthod to plot the data. i want 12 months jan to dec on x axis and y is data. to plot a simple graph i took a mean and SD of all January(2012-2013-2014-2015) months , February months(2012-2013-2014-2015) and so on for all months. so i got January mean and SD , February mean and SD and same for others months. i attached that plot here. i want same plot but using boxplot. hope u understand my question

Answer 1

[Walter Roberson]

timeinfo = datevec(YourData(:,1));
month_of_entry = timeinfo(:,2);    %datevec second column of output is month of the year
boxplot(YourData(:,2), month_of_entry)

[pruth]

hey thanks. that works.....thank you so much, i thought it would be diificult