# input data
dta <- read.csv("C:/Users/USER/Desktop/nlsy86wide.csv")

# inspect data structure
str(dta)
## 'data.frame':    166 obs. of  23 variables:
##  $ id        : int  23901 25601 37401 40201 63501 70301 72001 76101 76801 77001 ...
##  $ sex       : chr  "Female" "Female" "Female" "Male" ...
##  $ race      : chr  "Majority" "Majority" "Majority" "Majority" ...
##  $ grade86   : int  0 0 0 0 1 0 0 0 0 0 ...
##  $ grade88   : int  2 1 2 1 3 2 1 3 2 2 ...
##  $ grade90   : int  3 3 5 2 4 3 3 4 5 4 ...
##  $ grade92   : int  5 6 6 5 6 5 5 6 6 5 ...
##  $ age86year : int  6 6 6 5 7 5 6 7 6 6 ...
##  $ age88year : int  8 8 8 8 9 8 8 9 9 8 ...
##  $ age90year : int  10 10 10 9 11 10 10 11 11 10 ...
##  $ age92year : int  12 12 12 12 13 12 12 13 13 12 ...
##  $ age86month: int  67 66 67 60 78 62 66 79 76 67 ...
##  $ age88month: int  96 95 95 91 108 93 94 109 104 94 ...
##  $ age90month: int  119 119 122 112 132 117 118 131 128 117 ...
##  $ age92month: int  142 143 144 139 155 139 140 154 151 139 ...
##  $ math86    : num  14.29 20.24 17.86 7.14 29.76 ...
##  $ math88    : num  15.5 36.9 22.6 21.4 50 ...
##  $ math90    : num  38.1 52.4 53.6 53.6 47.6 ...
##  $ math92    : num  41.7 58.3 58.3 51.2 71.4 ...
##  $ read86    : num  19.05 21.43 21.43 7.14 30.95 ...
##  $ read88    : num  29.8 32.1 45.2 21.4 50 ...
##  $ read90    : num  28.6 45.2 69 50 63.1 ...
##  $ read92    : num  45.2 57.1 78.6 59.5 82.1 ...
# examine first 6 lines
head(dta)
##      id    sex     race grade86 grade88 grade90 grade92 age86year age88year
## 1 23901 Female Majority       0       2       3       5         6         8
## 2 25601 Female Majority       0       1       3       6         6         8
## 3 37401 Female Majority       0       2       5       6         6         8
## 4 40201   Male Majority       0       1       2       5         5         8
## 5 63501   Male Majority       1       3       4       6         7         9
## 6 70301   Male Majority       0       2       3       5         5         8
##   age90year age92year age86month age88month age90month age92month    math86
## 1        10        12         67         96        119        142 14.285714
## 2        10        12         66         95        119        143 20.238095
## 3        10        12         67         95        122        144 17.857143
## 4         9        12         60         91        112        139  7.142857
## 5        11        13         78        108        132        155 29.761905
## 6        10        12         62         93        117        139 14.285714
##     math88   math90   math92    read86   read88   read90   read92
## 1 15.47619 38.09524 41.66667 19.047619 29.76190 28.57143 45.23810
## 2 36.90476 52.38095 58.33333 21.428571 32.14286 45.23810 57.14286
## 3 22.61905 53.57143 58.33333 21.428571 45.23810 69.04762 78.57143
## 4 21.42857 53.57143 51.19048  7.142857 21.42857 50.00000 59.52381
## 5 50.00000 47.61905 71.42857 30.952381 50.00000 63.09524 82.14286
## 6 36.90476 55.95238 63.09524 17.857143 46.42857 64.28571 96.42857
library(tidyverse)
## -- Attaching packages ---------------- tidyverse 1.3.0 --
## √ ggplot2 3.3.2     √ purrr   0.3.4
## √ tibble  3.0.3     √ dplyr   1.0.2
## √ tidyr   1.1.2     √ stringr 1.4.0
## √ readr   1.3.1     √ forcats 0.5.0
## -- Conflicts ------------------- tidyverse_conflicts() --
## x dplyr::filter() masks stats::filter()
## x dplyr::lag()    masks stats::lag()
#