How to calculate 8-days accumulated rainfall on a daily time series, using R?
<p>I am trying to calculate a 8-days accumulated rainfall, with this code, but it seems to not work well.</p>

<p>chuva$Precipitacao it is my vector of daily rainfall, of length 5601.</p>

<pre><code> rain&lt;-chuva$Precipitacao 
j=1
rain8&lt;-vector()
for (i in 1:800){
   rain8&lt;-rbind(rain8, (rain[j]+rain[j+1]+rain[j+2]+rain[j+3]+
                     rain[j+4]+rain[j+5]+rain[j+6]+rain[j+7]));
  j=i+7
}
</code></pre>