Reputation: 663
This question is asking which command to use given the following situation:
Objective: Calculate mean of iris$Sepal.Length.
Constraint: Do not include the iris$Species 'setosa'.
My Work:
data(iris)
levels(iris$Species)
output: setosa, versicolor, and virginica
mean(iris$Sepal.Length, which(iris$Species != 'setosa'))
output: error message 'incompatible dimensions'
---
This demo is a stand-in for my own dataset, where I want to calculate a function for a variable (such as Sepal.Length) that excludes levels from a second variable (such as Species). I believe my personal dataset and this stand-in demo are comparable.
Perhaps which() is not the appropriate command. What is?
Upvotes: 0
Views: 56
Reputation: 5951
You were close, try this
mean(iris$Sepal.Length[which(iris$Species != 'setosa')])
or
mean(iris$Sepal.Length[iris$Species != 'setosa'])
or
mean(iris[iris$Species!= "setosa", "Sepal.Length"])
Upvotes: 2