title: Observations in the environment of R studio but empties dataframes
body: <p>I am working with precipitation data in R but I had a problem that I cannot solve. I will put here the code to be clearer. I have precipitation data (mm/h) for 47 meteorological stations with minute data, but I need the data hourly and a file with all the stations to then interpolate. The problem is, in this moment, to create that dataframes with the 47 stations, these dataframes must be structured normally by 47  observations and 3 variables.</p>
  <p>But the problem is that in the environment I can see that apparently the process is correct, but when I open the dataframe I get surprised because there is only one value as you can see in the image.</p>
  <p><a href="https://i.stack.imgur.com/7AKUn.png" rel="nofollow noreferrer">Look the dataframe 071212</a></p>
  <p>This is the code I have used to generate the dataframes.</p>
  <pre><code>setwd(&quot;D:/Escritorio/ohiiunam/estaciones&quot;)
  
  temp &lt;- list.files(pattern=&quot;*.csv&quot;)
  
  lista = lapply(temp, read.csv)
  
  lista&lt;-data.table::rbindlist(lista)
  
  n_last &lt;- 6                                
  lista$id2&lt;- substr(lista$id, nchar(lista$id) - n_last + 1, nchar(lista$id)) 
  
  unicos &lt;- unique(lista$id2)
  
  fun &lt;- function(i) {
    i&lt;-lista %&gt;% select(id, intensidad.mm.h, id2) %&gt;% filter(lista$id2==i) 
  }
  
  for (i in unicos) {
    i &lt;- as.data.frame(fun(i))
  }
  </code></pre>