Cumulative sum of time series into one plot

Hello eveyone, the following relies on the following Exchange file: downloaded GDP data for selected countires:

startDate = strcat('1996-01-01');
endDate = strcat('2017-12-31');


[calDate, GDPdeu]=fred2read('DEUGDPNQDSMEI',startDate,endDate);
[~, GDPfra]=fred2read('FRAGDPNQDSMEI',startDate,endDate);
[~, GDPita]=fred2read('ITAGDPNQDSMEI',startDate,endDate);
[~, GDPesp]=fred2read('ESPGDPNQDSMEI',startDate,endDate);
[~, GDPaut]=fred2read('AUTGDPNQDSMEI',startDate,endDate);
[~, GDPbel]=fred2read('BELGDPNQDSMEI',startDate,endDate);
[~, GDPfin]=fred2read('FINGDPNQDSMEI',startDate,endDate);
[~, GDPirl]=fred2read('IRLGDPNQDSMEI',startDate,endDate);
[~, GDPlux]=fred2read('LUXGDPNQDSMEI',startDate,endDate);
[~, GDPnld]=fred2read('NLDGDPNQDSMEI',startDate,endDate);
[~, GDPprt]=fred2read('PRTGDPNQDSMEI',startDate,endDate);

for i=0:21
   calDateYear(i+1) = calDate(4*i+2);
   GDPdeuYear(i+1) = 1000000* (GDPdeu(4*i+1)+GDPdeu(4*i+2)+GDPdeu(4*i+3)+GDPdeu(4*i+4));
   GDPitaYear(i+1) = 1000000* (GDPita(4*i+1)+GDPita(4*i+2)+GDPita(4*i+3)+GDPita(4*i+4));
   GDPfraYear(i+1) = 1000000* (GDPfra(4*i+1)+GDPfra(4*i+2)+GDPfra(4*i+3)+GDPfra(4*i+4));
   GDPespYear(i+1) = 1000000* (GDPesp(4*i+1)+GDPesp(4*i+2)+GDPesp(4*i+3)+GDPesp(4*i+4));
   GDPautYear(i+1) = 1000000* (GDPaut(4*i+1)+GDPaut(4*i+2)+GDPaut(4*i+3)+GDPaut(4*i+4));
   GDPbelYear(i+1) = 1000000* (GDPbel(4*i+1)+GDPbel(4*i+2)+GDPbel(4*i+3)+GDPbel(4*i+4));
   GDPfinYear(i+1) = 1000000* (GDPfin(4*i+1)+GDPfin(4*i+2)+GDPfin(4*i+3)+GDPfin(4*i+4));
   GDPirlYear(i+1) = 1000000* (GDPirl(4*i+1)+GDPirl(4*i+2)+GDPirl(4*i+3)+GDPirl(4*i+4));
   GDPluxYear(i+1) = 1000000* (GDPlux(4*i+1)+GDPlux(4*i+2)+GDPlux(4*i+3)+GDPlux(4*i+4));
   GDPnldYear(i+1) = 1000000* (GDPnld(4*i+1)+GDPnld(4*i+2)+GDPnld(4*i+3)+GDPnld(4*i+4));
   GDPprtYear(i+1) = 1000000* (GDPprt(4*i+1)+GDPprt(4*i+2)+GDPprt(4*i+3)+GDPprt(4*i+4));
end

Basically, I created new vairable showing yearly rather than quarterly GDP.

Now I want to show the shares of each country's GDP graphically, compared to the overall amunt of the GDP. What i would like to do is to plot GDPdeuYear(i+1), GDPdeuYear(i+1) + GDPitaYear(i+1), ... In order to "add up* the plot of every country. But I am not very successfull in doing it. I'm also aware that there should be a more elegant way to do it. Additionaly, it would be nice to have a (differently) colored area under each line to make comparison possible. Can anyone help me?

[Jan]

By the way, startDate = strcat('1996-01-01') is exactly the same as:

startDate = '1996-01-01';

Omit the strcat for simplicity. A further simplification:

% (GDPdeu(4*i+1)+GDPdeu(4*i+2)+GDPdeu(4*i+3)+GDPdeu(4*i+4))
sum(GDPdeu(4*i+ (1:4))

I do not understand this sentence:

"show the shares of each country's GDP graphically, compared to the overall amunt of the GDP. What i would like to do is to plot GDPdeuYear(i+1), GDPdeuYear(i+1) + GDPitaYear(i+1), ... In order to "add up* the plot of every country."

Do have to know what "shares" are?

The code would get easier, if you do not hide the detail of the country inside the name of the variable like in "GDPdeuYear". If you use an struct array instead, the list of countries can be processed in a loop:

[calDate, GDP(1).data]=fred2read('DEUGDPNQDSMEI',startDate,endDate);
GDB(1).country = 'deu'

[Marko Rajkovic]

@Jan by that part I mean:

If I just plot every country's GDP the upper curve shows the time-series for the country that has the highest GDP. Instead, the upper curve should diplay the sum of all GDPs. Here is an example.

What I need instead is:

Here you can see that if a color covers a bigger area, then this is a signal that that country has a bigger share of the overall GDP.

[Jan]

Does this mean, that you want an area() plot? See: https://www.mathworks.com/help/matlab/ref/area.html