Data extraction of dates

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Asanka Subasinghe 2020-3-24

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评论： Walter Roberson 2020-3-25

I have a column of data with rainfall on each day, from 2004 to 2016. I want to be able to extract the rainfall data for each day and store that data into columns of months for each year. I have created a loop that finds the end day of all months from 2004 to 2016, but am having trouble now extracting the information.

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Mohammad Sami 2020-3-24

编辑：Mohammad Sami 2020-3-24

Create a vector to store the index of the days (rows) you want to extract. Then you can simply subset.

Asanka Subasinghe 2020-3-24

I need some sort of loop because theres more than 4000 data points

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Walter Roberson 2020-3-24

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编辑：Walter Roberson 2020-3-24

在 MATLAB Online 中打开

Dv = Dates(:) ; 
Output = accumarray([day(Dv), month(Dv), year(Dv)-2003], Rainfall(:), [31 12 13], [], nan);

The result will be a 3d array with one pane for each year, with rows being day numbers, columns being month numbers. Unused entries such as shorter months or missing data will be set to nan

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Asanka Subasinghe 2020-3-25

在 MATLAB Online 中打开

clc;clear all;close all
filename='Data Q2 (2).xlsx';
data=(readtable(filename))
dandenongnum=data(:,2);
dandenongdate=data(:,1);
Dv=dandenongdate;
Output = accumarray([day(Dv), month(Dv), year(Dv)-2003], dandenongnum, [31 12 13], [], nan);

Walter Roberson 2020-3-25

在 MATLAB Online 中打开

clc;clear all;close all
filename='Data Q2 (2).xlsx';
data=(readtable(filename))
dandenongnum=data{:,2};
dandenongdate=data{:,1};
 Dv=dandenongdate;
 Output = accumarray([day(Dv), month(Dv), year(Dv)-2003], dandenongnum, [31 12 13], [], nan);