kNN tricks & tips I: weighting donors
A variation of kNN imputation that is frequently applied uses the so-called distance-weighted aggregation. What this means is that when we aggregate the values from the neighbors to obtain a replacement for a missing value, we do so using the weighted mean and the weights are inverted distances from each neighbor. As a result, closer neighbors have more impact on the imputed value.
In this exercise, you will apply the distance-weighted aggregation while imputing the tao data. This will only require passing two additional arguments to the kNN() function. Let's try it out!
แบบฝึกหัดนี้เป็นส่วนหนึ่งของหลักสูตร
Handling Missing Data with Imputations in R
คำแนะนำการฝึกหัด
- Load the
VIMpackage. - Impute
humiditywith kNN using distance-weighted mean for aggregating neighbors; you will need to specify thenumFunandweightDistarguments. - The margin plot to view the results has been already coded for you.
แบบฝึกหัดเชิงโต้ตอบแบบลงมือทำ
ลองทำแบบฝึกหัดนี้โดยเติมโค้ดตัวอย่างนี้ให้สมบูรณ์
# Load the VIM package
___(___)
# Impute humidity with kNN using distance-weighted mean
tao_imp <- ___(tao,
k = 5,
variable = "humidity",
___ = ___,
___ = ___)
tao_imp %>%
select(sea_surface_temp, humidity, humidity_imp) %>%
marginplot(delimiter = "imp")