MATLAB Answers

How to plot monthly data for 31 years on the same plot?

1 view (last 30 days)
Leo Tu
Leo Tu on 30 Jun 2021
Edited: Seth Furman on 1 Jul 2021
I have a table with the first column labelled month_Date. It contains the months from Jan 1987 to Jan 2020. The Second column is just a groupcount. The third column is labelled mean_MeanSoilTemperatureAt1MdegCIDWMean and it contains the mean soil temperature for each of the months. I need to make a plot such that the x-axis is labelled with the months and the y-axis labelled soil temperature. Then, I need the lines of the plot to be each years values and for each line to be a specific colour. If anyone could help, it would be much appreciated.
  1 Comment
Leo Tu
Leo Tu on 30 Jun 2021
Update: I orginally had a table called T with dates from 01/01/1987 00:00 to 01/01/2020 00:00 and I used the following script to group the dates into months and to find the mean of soil temperature for each month:
TT = groupsummary(T,1,"Month","Mean",38);
where 1 is the column number for the dates in T and 38 is the column number for soil temperature in T.
Then TT is my new table as mentioned in my original question post.

Sign in to comment.

Accepted Answer

Seth Furman
Seth Furman on 1 Jul 2021
Edited: Seth Furman on 1 Jul 2021
It is probably easier to store the data in a timetable and use retime to get the monthly averages.
tt = timetable(datetime(2000,1,1)+calmonths(1:100)',(1:100)')
tt = 100×1 timetable
Time Var1 ___________ ____ 01-Feb-2000 1 01-Mar-2000 2 01-Apr-2000 3 01-May-2000 4 01-Jun-2000 5 01-Jul-2000 6 01-Aug-2000 7 01-Sep-2000 8 01-Oct-2000 9 01-Nov-2000 10 01-Dec-2000 11 01-Jan-2001 12 01-Feb-2001 13 01-Mar-2001 14 01-Apr-2001 15 01-May-2001 16
tt = retime(tt,'monthly','mean')
tt = 100×1 timetable
Time Var1 ___________ ____ 01-Feb-2000 1 01-Mar-2000 2 01-Apr-2000 3 01-May-2000 4 01-Jun-2000 5 01-Jul-2000 6 01-Aug-2000 7 01-Sep-2000 8 01-Oct-2000 9 01-Nov-2000 10 01-Dec-2000 11 01-Jan-2001 12 01-Feb-2001 13 01-Mar-2001 14 01-Apr-2001 15 01-May-2001 16
Then, we can find the list of years covered by our data ...
years = unique(tt.Time.Year,'sorted')
years = 9×1
2000 2001 2002 2003 2004 2005 2006 2007 2008
... and plot them serially ...
figure
hold on
for i = 1:length(years)
ttYear = tt(tt.Time.Year == years(i),:);
plot(ttYear.Time,ttYear.Var1);
end
legend(string(years));
hold off
... or plot them against the months of the year by shifting all the datetime x-values to the same arbitrary year.
figure
hold on
for i = 1:length(years)
ttYear = tt(tt.Time.Year == years(i),:);
ttYear.Time.Year = 2000; % set all datetime x-values to the same arbitrary year
plot(ttYear.Time,ttYear.Var1);
end
xtickformat('MMM');
legend(string(years));
hold off

More Answers (1)

KSSV
KSSV on 30 Jun 2021
Let T be your table.
thedates = T.(1) ;
val = T.(3) ;
[Y,MO,D,H,MI,S] = datevec(thedates) ;
[c,ia,ib] = unique(Y) ;
figure(1)
hold on
for i = 1:length(c)
plot(thedates(ib==i),val(ib==i))
end
legend
  2 Comments
Leo Tu
Leo Tu on 30 Jun 2021
Sorry @KSSV I made a slight error. when I try using my table (TT) I get an error regarding datevec, stating that the input was was not an array of character vectors or strings. Sorry for the confusion. When I use my orginal table (T) then I get the plot I have shown above.

Sign in to comment.

Products


Release

R2021a

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by