在表格中打印精確的兩個十進制數字？

Question

以下腳本用於打印具有單位根測試結果的表格。你可以自己嘗試一下代碼。

library(vars) 
Canada = data.frame(Canada) 
library(urca) 
library(stargazer) 
library(dplyr) 

table_adf = function(DF, ...){ 
    var_list = as.list(unlist(list(...))) 
    if(length(var_list) == 0){ 
    subset = DF 
    var_list = as.list(names(DF)) 
    }else{ 
    subset = select_(DF, .dots = var_list) 
    } 

    tests = lapply(subset, function(x, y){ 
    out1 = ur.df(x, type = "drift", selectlags = "BIC") 
    out2 = ur.df(x, type = "trend", selectlags = "BIC") 
    out3 = ur.pp(x, type = "Z-tau", model = "const", lags = "short") 
    out4 = ur.pp(x, type = "Z-tau", model = "trend", lags = "short") 
    out5 = ur.kpss(x, type = "mu", lags = "short") 
    out6 = ur.kpss(x, type = "tau", lags = "short") 
    return(list(out1, out2, out3, out4, out5, out6)) 
    }) 

    est_df = lapply(tests, function(x){ 
    data.frame(ADF_constant = x[[1]]@teststat[1], 
       ADF_trend = x[[2]]@teststat[1], 
       PP_const = x[[3]]@teststat[1], 
       PP_trend = x[[4]]@teststat[1], 
       KPSS_const = x[[5]]@teststat[1], 
       KPSS_trend = x[[6]]@teststat[1]) 
    }) 

    est_table = do.call(rbind, est_df) 
    est_table = round(est_table, 2) 
    critical_vals = data.frame(tests[[1]][[1]]@cval[1,], 
          tests[[1]][[2]]@cval[1,], 
          tests[[1]][[3]]@cval[1,], 
          tests[[1]][[4]]@cval[1,], 
          tests[[1]][[5]]@cval[1,-1], 
          tests[[1]][[6]]@cval[1,-1]) 

    est_table[, 1:4] = Map(function(x, y){ 
    ifelse(x < y[1], paste(x, "0.01"), 
      ifelse(x < y[2], paste(x, "0.05"), 
        ifelse(x < y[3], paste(x, "0.10"), paste(x, "")))) 
    }, est_table[, 1:4], critical_vals[, 1:4]) %>% data.frame(row.names = unlist(var_list)) 

    est_table[, 5:6] = Map(function(x, y){ 
    ifelse(x > y[3], paste(x, "0.01"), 
      ifelse(x > y[2], paste(x, "0.02"), 
        ifelse(x > y[1], paste(x, "0.05"), paste(x, "")))) 
    }, est_table[, 5:6], critical_vals[, 5:6]) %>% data.frame(row.names = unlist(var_list)) 

    stargazer(est_table, type = "text", summary = FALSE) 
} 

table_adf(Canada, "e", "prod", "rw", "U") 

輸出表：

===================================================================== 
    ADF_constant ADF_trend PP_const PP_trend KPSS_const KPSS_trend 
--------------------------------------------------------------------- 
e  -0.3  -2.73  0.15  -1.62 2.05 0.01 0.17 0.05 
prod -0.11  -2.02  0.26  -1.97 1.66 0.01 0.27 0.01 
rw -4.37 0.01 -2.82 -5.62 0.01 -2.81 2.12 0.01 0.43 0.01 
U  -2.22  -2.47  -1.72  -1.96  0.23  0.14 
--------------------------------------------------------------------- 

正如你可以看到的例子中，第一值顯示爲-0.3代替-0.30。我如何調整腳本，使每個測試結果都打印成一個有兩位小數的數字？

Answer 1

一個建議是定義一個新的paste函數。 E.g

pasteFix <- function(x, signLev){ 
    ifelse(nchar(as.character(abs(x)))<4, 
    paste(paste(x, "0", sep=""),signLev), 
    paste(x, signLev)) 
} 

（nchar<4佔逗號。abs()以除去-）。 然後在你的Map

est_table[, 1:4] = Map(function(x, y){ 
    ifelse(x < y[1], pasteFix(x, "0.01"), 
     ifelse(x < y[2], pasteFix(x, "0.05"), 
       ifelse(x < y[3], pasteFix(x, "0.10"), pasteFix(x, "")))) 
}, est_table[, 1:4], critical_vals[, 1:4]) %>% data.frame(row.names = 
    unlist(var_list)) 

est_table[, 5:6] = Map(function(x, y){ 
    ifelse(x > y[3], pasteFix(x, "0.01"), 
     ifelse(x > y[2], pasteFix(x, "0.02"), 
       ifelse(x > y[1], pasteFix(x, "0.05"), pasteFix(x, "")))) 
}, est_table[, 5:6], critical_vals[, 5:6]) %>% data.frame(row.names = 
unlist(var_list)) 

輸出代替舊paste功能則

===================================================================== 
    ADF_constant ADF_trend PP_const PP_trend KPSS_const KPSS_trend 
--------------------------------------------------------------------- 
e  -0.30  -2.73  0.15  -1.62 2.05 0.01 0.17 0.05 
prod -0.11  -2.02  0.26  -1.97 1.66 0.01 0.27 0.01 
rw -4.37 0.01 -2.82 -5.62 0.01 -2.81 2.12 0.01 0.43 0.01 
U  -2.22  -2.47  -1.72  -1.96  0.23  0.14 
---------------------------------------------------------------------