title: Attribute name to univariate time series object in R and ts
body: <p>I´m reading a CSV file with a structure similar to </p>
  
  <pre><code>ref_date;   value
  2017-01-31;  123123
  2017-02-28;   938384
  2017-03-30;   54536
  </code></pre>
  
  <p>so it has a monthly frequency. After giving up converting the dates on the ref_value column, I decided to use directly a conversion to ts:</p>
  
  <pre><code>df = read.csv(data_file, sep=';', header=T)
  df_ts = ts(df$value, frequency=12, start=c(2017,1))
  </code></pre>
  
  <p>and now I´m trying to do a linear regression with <code>lm</code>, but as my time series has no names, </p>
  
  <pre><code>names(df_ts)
  NULL
  </code></pre>
  
  <p>how can I either attribute names to the <code>ts</code> object or do a linear regression on it?</p>