Using NA in an If/Then statement

June 10, 2022

I want to create a new column called Egg_Number. If the row (every row is a specific nest) has no NA values then there are three eggs in the nest. If the row has an NA value for length_3, then there are two eggs. If the row has an NA value in length_3 AND length_2, then there is only 1 egg in the nest. I’m trying to figure out how to add this column and my only idea was using an if/else statement.

Something like so:

if (NIUS2021.ALL$length_3 = NA) { 
NIUS2021.ALL$Egg_Number = 2 }
else if (NIUS2021.ALL$length_3 = NA AND NIUS2021.ALL$length_2 = NA) {
NIUS2021.ALL$Egg_Number = 1 }
else {NIUS2021$.ALLEgg_Number = 3}

Here is my data set I’m using

> dput(head(NIUS2021.ALL))
structure(list(Niu = structure(1:6, .Label = c("1", "2", "3", 
"4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", 
"16", "17", "18", "19", "21", "22", "23", "25", "26", "27", "28", 
"29", "30", "31", "32", "33", "34", "35", "36", "37", "38", "39", 
"40", "41", "42", "43", "44", "45", "46", "47", "48", "49", "50", 
"51", "52", "53", "54", "55", "56", "57", "58", "59", "60", "61", 
"62", "63", "64", "65", "66", "67", "68", "69", "70", "71", "72", 
"73", "74", "75", "76", "906", "910", "915", "916", "917", "919", 
"920", "922", "924", "927", "928", "930", "931", "950", "951", 
"952", "953", "954", "955", "956", "957", "958", "959", "963"
), class = "factor"), totalV = c(183.1311069223, 189.09433326461, 
196.39045370996, 181.282560178575, 115.67490871467, 172.752941083985
), averageV = c(61.0437023074333, 63.0314444215367, 65.4634845699867, 
60.427520059525, 57.837454357335, 57.5843136946617), volume_1 = c(62.57592810342, 
67.75331569111, 71.51507045914, 62.28569026831, 58.639530945905, 
59.458291114465), volume_2 = c(60.45794961088, 64.6494663195, 
62.626512390435, 62.029110556805, 57.035377768765, 58.42423975
), volume_3 = c(60.097229208, 56.691551254, 62.248870860385, 
56.96775935346, NA, 54.87041021952), length_1 = c(67.07, 66.86, 
66.44, 64.94, 68.77, 63.41), length_2 = c(62.78, 63.27, 65.59, 
63.13, 62.81, 65.15), length_3 = c(68.28, 62.75, 63.41, 67.29, 
NA, 61.53), width_1 = c(43.86, 45.71, 47.11, 44.47, 41.93, 43.97
), width_2 = c(44.56, 45.9, 44.37, 45.01, 43.27, 43), width_3 = c(42.6, 
43.16, 44.99, 41.78, NA, 42.88)), class = c("grouped_df", "tbl_df", 
"tbl", "data.frame"), row.names = c(NA, -6L), groups = structure(list(
    Niu = structure(1:6, .Label = c("1", "2", "3", "4", "5", 
    "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "16", 
    "17", "18", "19", "21", "22", "23", "25", "26", "27", "28", 
    "29", "30", "31", "32", "33", "34", "35", "36", "37", "38", 
    "39", "40", "41", "42", "43", "44", "45", "46", "47", "48", 
    "49", "50", "51", "52", "53", "54", "55", "56", "57", "58", 
    "59", "60", "61", "62", "63", "64", "65", "66", "67", "68", 
    "69", "70", "71", "72", "73", "74", "75", "76", "906", "910", 
    "915", "916", "917", "919", "920", "922", "924", "927", "928", 
    "930", "931", "950", "951", "952", "953", "954", "955", "956", 
    "957", "958", "959", "963"), class = "factor"), .rows = structure(list(
        1L, 2L, 3L, 4L, 5L, 6L), ptype = integer(0), class = c("vctrs_list_of", 
    "vctrs_vctr", "list"))), class = c("tbl_df", "tbl", "data.frame"
), row.names = c(NA, -6L), .drop = TRUE))

Thank you for the help!

>Solution :

You may try

library(dplyr)

NIUS2021 %>%
  mutate(Egg_number = case_when(
    !is.na(length_1 * length_2 * length_3) ~ 3,
    is.na(length_3) & is.na(length_2) ~ 1,
    is.na(length_3) ~ 2,
    T ~ NA_real_
  ))

some of data

  Niu   length_1 length_2 length_3 Egg_number     key
  <fct>    <dbl>    <dbl>    <dbl>      <dbl>   <dbl>
1 1         67.1     62.8     68.3          3 282409.
2 2         66.9     63.3     62.8          3 282833.
3 3         66.4     65.6     63.4          3 289532.
4 4         64.9     63.1     67.3          3 266232.
5 5         68.8     62.8     NA            2 297048.
6 6         63.4     65.2     61.5          3 261957.