CODEWITHSUNDEEP
matlabdate
TYL
TYL

Reputation: 1637

how do I split a vector of dates into days?

I have a dataset with dates on 1 column and values on another column

'4/26/2016'  23
'4/26/2016'  25
'4/26/2016'  1
'4/27/2016'  10
'4/27/2016'  40
'4/27/2016'  67
'4/28/2016'  24
'4/28/2016'  13
'4/28/2016'  7
'4/28/2016'  99

How do I separate the values into different days? e.g., 4/27/2016 will have values of 10, 40 and 67 and so on. The dates might be different depending on the dataset that I am using so there is no fixed dates. Thanks!

Upvotes: 0

Views: 243

Answers (2)

Dan
Dan

Reputation: 45752

We don't know what data structure you are using so we'll just have to assume it:

%% Your data
dates = {'4/26/2016';'4/26/2016';'4/26/2016';'4/27/2016';...
    '4/27/2016';'4/27/2016';'4/28/2016';'4/28/2016';...
    '4/28/2016';'4/28/2016'};

values = [23; 25; 1; 10; 40; 67; 24; 13; 7; 99];

[uniqueDates,~,sub] = unique(dates)
valuesPerDate = accumarray(sub, values, [], @(x){x})

%OPTIONAL
combined = [uniqueDates, valuesPerDate]

I would actually recommend first converting your dates into the new datetime type, i.e. dates = datetime(dates) and then later combined = [num2cell(uniqueDates), valuesPerDate], but if not then at least use a more logical format such as 'yyyy-mm-dd' so that their alphabetical ordering is the same as their chronological ordering.

Upvotes: 2

OsJoe
OsJoe

Reputation: 259

%% Your data
date = {'4/26/2016';'4/26/2016';'4/26/2016';'4/27/2016';...
    '4/27/2016';'4/27/2016';'4/28/2016';'4/28/2016';...
    '4/28/2016';'4/28/2016'};

data = [23; 25; 1; 10; 40; 67; 24; 13; 7; 99];

%% First convert the date to datenum for ease
date = datenum(date,'mm/dd/yyyy');

%% Get the number of days 
unique_days = unique(date);

%% Loop through the different days and extract corresponding data
%% - You might want to add unique identifiers to the variable names
for idx = 1:length(unique_days)
curr_day = unique_days(idx);  % Get current date
idx_days = date == curr_day;  % indices of data for current date
data_results{idx} = data(idx_days);   % results
end

Upvotes: 2

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