How to plot monthly data for 31 years on the same plot?
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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.
Accepted Answer
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 = retime(tt,'monthly','mean')
Then, we can find the list of years covered by our data ...
years = unique(tt.Time.Year,'sorted')
... 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
4 Comments
Leo Tu
on 1 Jul 2021
Lejla Latifovic
on 26 Apr 2022
Is there a way to plot them against months but not set an arbitrary year so that each line still keeps its corresponding year. Some of the years have the same colours (e.g. above 2000 and 2007).
Do you mean the serial case above (copied below)?
tt = timetable(datetime(2000,1,1)+calmonths(1:100)',(1:100)');
tt = retime(tt,'monthly','mean');
years = unique(tt.Time.Year,'sorted');
f = 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
The colors repeat because, by default, only 7 colors are used. After the 7th line, the colors repeat. We can override this behavior by setting our own colors using the colororder function. When setting the color order, we can take advantage of predefined color maps such as parula and adapt them to the number of lines we have.
co = parula(numel(years));
colororder(f,co);
Lejla Latifovic
on 29 Apr 2022
Not quite like this, I have nine years of half-hourly data (I've converted it to daily and monthly) I want the x-axis to be months, January - December, and all of the years plotted against the montlhy x-axis. I was looking for a way to do this without setting an arbitrary year for all of the years like you have in the code above but it looks like there isn't another way to do this. Thanks for your response!
Thank you for the colour information, I will attempt this.
More Answers (1)
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
on 30 Jun 2021
Thank you for your response @KSSV. With this script however, I get this plot where the x-axis are labelled in years rather than months and the lines of yearly data are in one line and not overlapping. I have attached the plot for reference. I need the x-axis to be from Jan to Dec and then each yearly data (the coloured lines) to be overlapping. Thank you for your help @KSSV
Leo Tu
on 30 Jun 2021
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