R：如何将移动平均线应用于数据框中的列子集？

Question

I have a dataframe (training.set) that is 150 observations of 83 variables. I want to transform 82 of those columns with some moving averages. The problem is the results end up only being 150 numeric values (ie 1 column).

How would I apply the moving average function across each column individually in the data and keep the 83rd column unchanged? I feel like this is super simple, but I can't find a solution.

My current code

# apply moving average on training.set data to 82 of 83 rows
library(TTR)  #load TTR library for SMA functions
ts.sma <- SMA(training.set[,1:82], n = 10)
ts.sma

Thanks for your help.

Answer 1

apply(training.set[,1:82], 2, SMA, n=10)

请注意，这会将data.frame转换为矩阵-如果您需要将输出作为data.frame， data.frame(...)其包装在data.frame(...) 。