嗨，

我刚刚转置了一个大数据集，我意识到第一行没有列名。我包含了数据集的摘录，我尝试使用名称（df）[1]

df <- structure(list(Construction = c("3209.4", "3307.0", "3519.3", "3693.0", 
"3545.1", "3620.2"), Manufacturing = c(" 654.9", " 692.9", " 785.1", 
" 810.1", " 744.8", " 793.6")), row.names = c("1975 1Q", "1975 2Q", 
"1975 3Q", "1975 4Q", "1976 1Q", "1976 2Q"), class = "data.frame")


df
#>         Construction Manufacturing
#> 1975 1Q       3209.4         654.9
#> 1975 2Q       3307.0         692.9
#> 1975 3Q       3519.3         785.1
#> 1975 4Q       3693.0         810.1
#> 1976 1Q       3545.1         744.8
#> 1976 2Q       3620.2         793.6

^{由reprex包（v0.3.0）于2020-09-03创建}

devtools::session_info()
#> ─ Session info ───────────────────────────────────────────────────────────────
#>  setting  value                       
#>  version  R version 4.0.2 (2020-06-22)
#>  os       macOS Catalina 10.15.5      
#>  system   x86_64, darwin17.0          
#>  ui       X11                         
#>  language (EN)                        
#>  collate  en_AU.UTF-8                 
#>  ctype    en_AU.UTF-8                 
#>  tz       Australia/Melbourne         
#>  date     2020-09-03                  
#> 
#> ─ Packages ───────────────────────────────────────────────────────────────────
#>  package     * version date       lib source        
#>  assertthat    0.2.1   2019-03-21 [1] CRAN (R 4.0.2)
#>  backports     1.1.9   2020-08-24 [1] CRAN (R 4.0.2)
#>  callr         3.4.3   2020-03-28 [1] CRAN (R 4.0.2)
#>  cli           2.0.2   2020-02-28 [1] CRAN (R 4.0.2)
#>  crayon        1.3.4   2017-09-16 [1] CRAN (R 4.0.2)
#>  desc          1.2.0   2018-05-01 [1] CRAN (R 4.0.2)
#>  devtools      2.3.1   2020-07-21 [1] CRAN (R 4.0.2)
#>  digest        0.6.25  2020-02-23 [1] CRAN (R 4.0.2)
#>  ellipsis      0.3.1   2020-05-15 [1] CRAN (R 4.0.2)
#>  evaluate      0.14    2019-05-28 [1] CRAN (R 4.0.1)
#>  fansi         0.4.1   2020-01-08 [1] CRAN (R 4.0.2)
#>  fs            1.5.0   2020-07-31 [1] CRAN (R 4.0.2)
#>  glue          1.4.2   2020-08-27 [1] CRAN (R 4.0.2)
#>  highr         0.8     2019-03-20 [1] CRAN (R 4.0.2)
#>  htmltools     0.5.0   2020-06-16 [1] CRAN (R 4.0.2)
#>  knitr         1.29    2020-06-23 [1] CRAN (R 4.0.2)
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#>  memoise       1.1.0   2017-04-21 [1] CRAN (R 4.0.2)
#>  pkgbuild      1.1.0   2020-07-13 [1] CRAN (R 4.0.2)
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#>  rlang         0.4.7   2020-07-09 [1] CRAN (R 4.0.2)
#>  rmarkdown     2.3     2020-06-18 [1] CRAN (R 4.0.2)
#>  rprojroot     1.3-2   2018-01-03 [1] CRAN (R 4.0.2)
#>  sessioninfo   1.1.1   2018-11-05 [1] CRAN (R 4.0.2)
#>  stringi       1.4.6   2020-02-17 [1] CRAN (R 4.0.2)
#>  stringr       1.4.0   2019-02-10 [1] CRAN (R 4.0.2)
#>  testthat      2.3.2   2020-03-02 [1] CRAN (R 4.0.2)
#>  usethis       1.6.1   2020-04-29 [1] CRAN (R 4.0.2)
#>  withr         2.2.0   2020-04-20 [1] CRAN (R 4.0.2)
#>  xfun          0.16    2020-07-24 [1] CRAN (R 4.0.2)
#>  yaml          2.2.1   2020-02-01 [1] CRAN (R 4.0.2)
#> 
#> [1] /Library/Frameworks/R.framework/Versions/4.0/Resources/library