【问题标题】：R: creating a matrix using two id columns and the value column [duplicate]R：使用两个id列和值列创建矩阵[重复]
【发布时间】：2021-11-26 22:20:53
【问题描述】：

目的

我正在尝试为每个 id 组合使用两个 id 列（period1、period2）和值列（p）创建一个矩阵。它们是 t 检验的结果。我想制作一个方阵，显示每个 id 组合的 p 值，类似于相关矩阵。

样本数据

  t <-
  structure(list(period1 = c("(1) Start (178)", "(1) Start (178)", 
    "(1) Start (178)", "(1) Start (178)", "(2) Mature (217)", "(2) Mature (217)", 
    "(2) Mature (217)", "(3) COVID hit (117)", "(3) COVID hit (117)", 
    "(4) After COVID (79)"), period2 = c("(2) Mature (178)", "(3) COVID hit (178)", 
    "(4) After COVID (178)", "(5) Closing (178)", "(3) COVID hit (217)", 
    "(4) After COVID (217)", "(5) Closing (217)", "(4) After COVID (117)", 
    "(5) Closing (117)", "(5) Closing (79)"), p = c("0.0000 (****)", 
    "0.0000 (****)", "0.0000 (****)", "0.0055 (**)", "0.0003 (***)", 
    "0.0727 (ns)", "0.0000 (****)", "0.2050 (ns)", "0.0000 (****)", 
    "0.0000 (****)")), row.names = c(NA, -10L), class = "data.frame")

【问题讨论】：

标签： r matrix t-test

【解决方案1】：

可能我们需要重塑为“宽”格式

library(tidyr)
library(tibble)
library(dplyr)
t %>% 
   pivot_wider(names_from = period2, values_from = p) %>% 
   column_to_rownames('period1')

【讨论】：