几行代码，一个逼真的圣诞树，圣诞快乐

Posted 2022-01-14 qq_21478261

圣诞快乐～

 上代码

library(tidyverse)
library(rlang)
source("R/grow_tree.R")

# step1、插上树枝
angle_fun1 <- function(angle) angle + c(-0.1 * pi, 0.1 * pi)
length_fun1 <- function(length) 0.85 * length
surv_fun1 <- function() 0.9

set.seed(12345)
tree1 <- grow_tree(n_iter = 10, angle_fun = angle_fun1(angle), length_fun = length_fun1(length),
    surv_fun = surv_fun1(), verbose = FALSE)

# step2、生出树叶
angle_fun2 <- function(angle, generation) 
    w <- 1 - 1/generation
    a0 <- rnorm(1, 0.12 * w * pi, 0.05 * w * pi)
    angle + sample(c(-a0, a0))



length_fun2 <- function(length) rnorm(2, 0.9, 0.05) * length
surv_fun2 <- function(generation, n_iter) c(0.75 - (n_iter - generation[1])/(2 *
    n_iter), 0.95)

set.seed(999)
tree2 <- grow_tree(n_iter = 25, angle_fun2(angle, generation), length_fun2(length),
    surv_fun2(generation, 25), verbose = FALSE)


# step3、结上果子
tree2_clean <- clean_tree(tree2)
set.seed(13579)
baubles <- filter(tree2_clean, generation == 25, pos == 0) %>%
    sample_n(30)

p1 + geom_point(data = baubles, aes(x = x, y = y), fill = "#AA1243", col = 1, pch = 21,
    size = 5) + geom_point(data = baubles, aes(x = x, y = y), col = "white", alpha = 0.3,
    size = 1, position = position_nudge(x = -0.08, y = 0.08))

参考：R可视化23|Christmas tree