Data extraction of dates

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.

[SL: formatted question as text not code]

[Mohammad Sami]

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

[Asanka Subasinghe]

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

Answer 1

[Walter Roberson]

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

[Asanka Subasinghe]

I am receiving an error message that says

Error using accumarray

First input SUBS and third input SZ must satisfy

ALL(MAX(SUBS)<=SZ).

Can you please explain what each input of accumarray does?

Thanks

[Asanka Subasinghe]

current code is :

clc;clear all;close all
filename='Data Q2 (2).xlsx';
[num,txt,raw]=xlsread(filename);
dandenongdate=txt(2:end,1);
dandenongnum=num(:,1);

Dv = dandenongdate ; 
Output = accumarray([day(Dv), month(Dv), year(Dv)-2003], dandenongnum, [31 12 13], [], nan);

[Walter Roberson]

Use readtable so that you get datetime objects not date vectors.

[Asanka Subasinghe]

It tells me Error using day (line 37)

You cannot subscript a table using linear indexing (one

subscript) or multidimensional indexing (three or more

subscripts). Use a row subscript and a variable subscript.

What does it mean by row and variable subscript?

Thank you

[Asanka Subasinghe]

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]

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);