R 中的反向循环交互，如 Python

Question

here is my python loop code with output

peaks =range(2,10)
for i in range(len(peaks) - 1, -1, -1):
print(i)

# 7,6,5,4,3,2,1,0

but i do not know how to do this with R

suggest me please

Answer 1

I agree with Sosel. Nevertheless, here is working code:

peaks = 2:9
for(i in rev(0:(length(peaks)-1))) print(i)

Answer 2

in R

peaks <- c(2:10)
l <- length(peaks)
result <- l - peaks
result[result > 0]

returns

7 6 5 4 3 2 1

if you nedd a for loop, you can use this:

for(p in peaks){ifelse(l-p >= 0, print(l-p), NA)}