How do I perform cumulative adding of data by month and then plot it by year?

Question

Gareth Maver 2016-2-11

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/267677-how-do-i-perform-cumulative-adding-of-data-by-month-and-then-plot-it-by-year

评论： Star Strider 2016-2-12

I have data in a 8500x3 matrix - columns being year, month, day of each earthquake (all are in numerical representation - e.g. 1985 01 23). The data is in chronological order, with oldest first. As the number of earthquakes varies per day, the number of rows dedicated to each day/month/year changes.

I need to make a plot of cumulative number of earthquakes per month. I know I have to assign a one to every earthquake, but my problem comes in the cumulative adding. How do I add the data from one month in a given year to the next month? The problem arises due to the changing year as well.

Example of data:

[1985 01 01; 1985 01 12; 1985 01 14; 1985 01 25; 1985 03 02; 1985 06 16; 1985 06 18; 1985 11 09; 1986 01 01; 1986 01 30] ...

I hope I explained this easily.

Thanks, Gareth

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Star Strider 2016-2-11

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/267677-how-do-i-perform-cumulative-adding-of-data-by-month-and-then-plot-it-by-year#answer_209453

在 MATLAB Online 中打开

I don’t understand your Question and your ‘desired output’. This accumulates the total number in each month, and then the cumulative sum:

Seism = [1985 01 01; 1985 01 12; 1985 01 14; 1985 01 25; 1985 03 02; 1985 06 16; 1985 06 18; 1985 11 09; 1986 01 01; 1986 01 30];
SeismDN = datenum([Seism(:, 1:2) ones(size(Seism,1),1) zeros(size(Seism,1),3)]);
[SeismU,~,Idx] = unique(SeismDN,'stable');
SeisHist = accumarray(Idx,1);
Result = [str2num(datestr(SeismU, 'yyyy mm')) cumsum(SeisHist)]
Result =
        1985           1           4
        1985           3           5
        1985           6           7
        1985          11           8
        1986           1          10

9 个评论
显示 7更早的评论隐藏 7更早的评论

Gareth Maver 2016-2-12

编辑：Gareth Maver 2016-2-12

在 MATLAB Online 中打开

Is there anyway of plotting one continuous line instead of steps?

Basically I am wanting to recreate this figure but with the cumulative sum plotted at monthly intervals - i.e. more line detail is wanted in between the year ticks.

I have this code which creates the above figure:

    long = data(:,1) ;
    lati = data(:,2) ;
    year = data(:,3) ;
    month = data(:,4) ; 
    mag = data(:,6) ;
 for i = 1:length(mag)
    if mag(i) < 3 
        mag(i) = NaN ;
        lati(i) = NaN ;
        long(i) = NaN ;
        year(i) = NaN ;
        month(i) = NaN ;
    end
 end
    cum_year = [1985:1:2015] ;
    n = zeros(length(cum_year),1) ;
    cum_year = cum_year' ;
    for j = 1:length(n)
     for i = 1:length(mag) ;
         if year(i) == cum_year(j)
             n(j) = n(j)+1 ;
         end
     end
    end
    year_sum = zeros(length(n),1) ;    
    for i = 1:length(n) ;
       year_sum(i) = sum(n(1:i)) ;
    end
figure ; 
plot(cum_year(1:24),year_sum(1:24),'b','LineWidth',1.5) ;
hold on
plot(cum_year(24:29),year_sum(24:29),'Color',[0.0 0.8 0.3],'LineWidth',1.5) ;
plot(cum_year(29:31),year_sum(29:31),'r','LineWidth',1.5) ;

So is there anyway of a cumulative sum on a monthly basis, where the year is changing?

Gareth Maver 2016-2-12

Basically there is another column with earthquake magnitude values in it - ranging from 2.0 up to about 5.0. How would I code to only count the earthquakes above value 3.0 for the cumulative sum?

Star Strider 2016-2-12

在 MATLAB Online 中打开

This is how I would edit the original date and magnitude matrix:

datenms = datenum(bsxfun(@plus, [1985 01 01], [zeros(20,1) [1:20]' zeros(20,1)]));  % Create Dates
Data = [datenms rand(20,1)*3.3+2];                                                  % All Dates & Magnitudes
Data3 = Data(Data(:,2) > 3,:);                                                      % Select Magnitude > 3

If you wanted only the dates, in this example you would select ‘Data3(:,1)’.

请先登录，再进行评论。