你如何在 R 中制作虚拟数据集？
How do you make a dummy dataset in R?
我如何制作一个数据集，其中每个“站点”、“季节”、“年份”和“物种名称”都完全交叉（每个站点在每个 year/season 期间都被访问过，并且每个物种都可以已在任何时间和地点捕获 -> 即 5 个地点 x 2 个季节 x 2 年 x 2 个物种 = df 大小为 40x5)。
df <- data.frame(site = rep(c("1", "2", "3", "4", "5"), each = 2),
season = rep(c("dry", "wet"), each = 10),
year = rep(c(2019, 2020), each = 10),
species_name = rep(c("Sailfin molly", "Hardhead silverside"), each = 10),
num = sample(x = 0:15, size = 20, replace = TRUE))
您可以使用 expand.grid() 函数：
library(tidyverse)
site <- c("1", "2", "3", "4", "5")
season <- c("dry", "wet")
year <- c(2019, 2020)
species_name <- c("Sailfin molly", "Hardhead silverside")
num <- sample(x = 0:15, size = 40, replace = TRUE)
df <- data.frame(expand.grid(site, season, year, species_name) %>% mutate(num = num))
colnames(df) <- c("site", "season", "year", "species_name", "num")
我如何制作一个数据集，其中每个“站点”、“季节”、“年份”和“物种名称”都完全交叉（每个站点在每个 year/season 期间都被访问过，并且每个物种都可以已在任何时间和地点捕获 -> 即 5 个地点 x 2 个季节 x 2 年 x 2 个物种 = df 大小为 40x5)。
df <- data.frame(site = rep(c("1", "2", "3", "4", "5"), each = 2),
season = rep(c("dry", "wet"), each = 10),
year = rep(c(2019, 2020), each = 10),
species_name = rep(c("Sailfin molly", "Hardhead silverside"), each = 10),
num = sample(x = 0:15, size = 20, replace = TRUE))
您可以使用 expand.grid() 函数：
library(tidyverse)
site <- c("1", "2", "3", "4", "5")
season <- c("dry", "wet")
year <- c(2019, 2020)
species_name <- c("Sailfin molly", "Hardhead silverside")
num <- sample(x = 0:15, size = 40, replace = TRUE)
df <- data.frame(expand.grid(site, season, year, species_name) %>% mutate(num = num))
colnames(df) <- c("site", "season", "year", "species_name", "num")