How to repeat the same function in a matrix, changing a parameter of the function-CodePudding

I am learning to generate loops. I have this function from "betapart" package:

beta.diversity <- beta.sample(x, index.family="Sorensen", sites= n, samples= n)

where

x: data frame, where rows are sites and columns are species.

index.family: family of dissimilarity indices, partial match of "sorensen" or "jaccard".

sites: number of sites for which multiple-site dissimilarities will be computed. If not specified, default is all sites. samples: number of repetitions. If not specified, default is 1.

What I need is to run the same function in a matrix, but increasing the sites one at a time (some matrix have 1000 sites)

I thought that with the "lapply" function it might work, but I can't think of how.

Thank you!

CodePudding user response：

See how a generic loop works:

fruits <- c("apple", "peach", "pear")

# Use the elements in a vector directly
for(fruit in fruits){
  print(fruit)
}

# You can also use the index of each element
for(i in 1:length(fruits)){
  print(fruits[i])
}

See how a generic lapply works:

lapply(fruits, print)

Get example data from the betapart package:

library(betapart)

data(bbsData)
dat <- bbs2000[,1:10]

With a loop:

# Retain results
results <- list()

# Loop over each number of sites
allnsites = c(2:10)

for(i in 1:length(allnsites)){
  beta.diversity <- beta.sample(dat, index.family="sorensen", sites= allnsites[i], samples= 1)
  # Report number of sites in each iteration
  beta.diversity$sites <- allnsites[i]
  results[[i]] <- beta.diversity
}

With lapply():

lapply(allnsites, FUN = beta.sample, x = dat, index.family = "sorensen", samples = 1)