Error in eval(expr, envir, enclos) - contradiction?

Question

Edited to give a fuller example of code and specific issue

I\'m writing a function to produce time series plots of stock prices. However, I\'m getting the followi

Answer 1

The error occur because you use df[, 7] in gglpot2, use column name Adj.Close will fix the problem.

 g <- ggplot(df, aes(x= as.Date(Date, format= "%Y-%m-%d"),
                  y= Adj.Close)) + geom_point(size=1)

In fact the error , it is a scoping error. aes can't find the df environnement. It tries to look for it the global scope .

if you you want to use use indexing calls , you can use aes_string for example , and manipulate strings not expressions

plot.prices <- function(df) {
  require(ggplot2)

  df$Date <- as.Date(df$Date, format= "%Y-%m-%d")

  g <- ggplot(df, aes_string(x= 'Date',
                      y= colnames(df)[7])) + geom_point(size=1)

  # ... code not shown...
  g
}