如何编写循环来重复计算模拟次数的分数？答案

【问题标题】：How to write a loop to calculate a score for the number of simulations repeatedly?如何编写循环来重复计算模拟次数的分数？
【发布时间】：2015-11-11 02:21:05
【问题描述】：

我需要一个非常简单的循环，从 multiphylo 对象中获取每棵系统发育树，并计算每棵树的 Ic 并将其放入数据框中。对不起，如果它这么简单，我是 R 新手，我想不通！

    library(apTreeshape)
    library(phytools)
   multi_trees<- pbtree(b=0.5, d=0, n=200, t=NULL, scale=NULL, 
  nsim=50, type="continuous", extant.only=TRUE) ### simulate 50 trees stored as multiphylo object
    converted_tree <- as.treeshape(multi_trees[[nsim=1]]) ## each tree need to be converted to class treeshapes using following function

 Ic <- colless(converted_tree, norm = NULL) #And finally calculate Ic for each tree

【问题讨论】：

标签： r loops tree phylogeny

【解决方案1】：

循环很简单，所以我假设它是不言自明的。

    library(apTreeshape)
    library(phytools)

    # simulate 50 trees stored as multiphylo object
    multi_trees<- pbtree(b=0.5, d=0, n=200, t=NULL, scale=NULL, nsim=50, type="continuous", extant.only=TRUE)

    # make data.frame for results
    Ic <- matrix(nrow=50, ncol=2)
    Ic <- data.frame(Ic)
    colnames(Ic) <- c("sim", "Ic")

    # loop
    for (i in 1:50) {
        converted_tree <- as.treeshape(multi_trees[[i]])
        Ic[i,1] <- i # get simulation number
        Ic[i,2] <- colless(converted_tree, norm = NULL) # get Ic
    }

    Ic

【讨论】：