Displaying 1 result from an estimated 1 matches for "pr_mean".
2008 Jul 08
6
Question: Beginner stuck in a R cycle
Dear All,
I have a database of 200 observations named myD.
In the dataframe there are a column named code (with codes varying from 1 to 77), a column named "prevalence" with some quantitative measurements are given and an column named Pr_mean, with no values.
I would like to set a cycle to compute the average of prevalence values for each different code and store the averages under the empty field Pr_mean.
This is what I wrote:
# Set a cycle
for (i in 1:nrow(myD)) {
mycode = myD$code[i]
mymean[i] = mean(prevalence)
myD$Pr_mean[i] = m...