title: STL function for hourly / minute data
body: <p>I have a time series that I want to decompose using STL. The data has 1 row per min. I have the data for 10 days (the dataset is the one that comes pre-loaded with twitter's anomaly detection API)  and I want to find seasonality within a day (e.g. activity peaks from 9pm to 11pm)</p>
  
  <p>While decomposing with <code>STL</code> however, I get an error </p>
  
  <blockquote>
    <p>"series is not periodic or has less than 2 periods".</p>
  </blockquote>
  
  <p>I understand this is because the time frame of data should be >2yrs. However since I want to check seasonality within a day , is there a way to tell <code>STL</code> to look for seasonality within a day ? </p>
  
  <p>I tried using frequency option in <code>xts</code> while converting to time series format but doesn't work (1440 = no. of minutes in a day) </p>
  
  <pre><code>install.packages("devtools")
  devtools::install_github("twitter/AnomalyDetection")
  library(AnomalyDetection)
  library(xts)
  
  #data is part of the pacakage anomaly detection 
  data(raw_data)
  View(raw_data)
  
  #converting raw_data to xts format 
  
  raw_data_ts &lt;- ts(raw_data$count, as.POSIXct(raw_data$timestamp, format='%m-%d-%y %H:%M:%S'), frequency = 1440)
  raw_data_ts1&lt;-as.ts(raw_data_ts)
  
  # Using STL for seasonal decomposition 
  modelStl &lt;- stl(raw_data_ts1, s.window = "periodic")
  </code></pre>