NA row in brsmatch() result

[SusanJiao20]

df1 and df2 both contain NA in treatment time, the results returned from brsmatch contain the matched pairs and a row of NA.

library(rsmatch)
library(reprex)
#> Warning: package 'reprex' was built under R version 4.0.3
df1 <- data.frame(
  hhidpn = rep(1:3, each = 3),
  wave = rep(1:3, 3),
  treatment_time = rep(c(2,3,NA), each = 3),
  X1 = c(2,2,2,3,3,3,9,9,9),
  X2 = rep(c("a","a","b"), each = 3),
  X3 = c(9,4,5,6,7,2,3,4,8),
  X4 = c(8,9,4,5,6,7,2,3,4)
)
brsmatch(n_pairs = 1, df = df1, id = "hhidpn", time = "wave",
         trt_time = "treatment_time", optimizer = "glpk")
#>   hhidpn pair_id type
#> 1      1       1  trt
#> 2      2       1  all
#> 3      3      NA <NA>

df2 <- data.frame(
  hhidpn = rep(1:5, each = 3),
  wave = rep(1:3, 5),
  treatment_time = rep(c(2,3,2,3,NA), each = 3),
  X1 = c(2,2,2,3,3,3,9,9,9,10,10,10,7,7,7),
  X2 = rep(c("a","a","b"), each = 5),
  X3 = c(9,4,5,6,7,2,3,4,8,5,7,8,5,8,7),
  X4 = c(8,9,4,5,6,7,2,3,4,6,4,2,5,7,3)
)
brsmatch(n_pairs = 2, df = df2, id = "hhidpn", time = "wave",
         trt_time = "treatment_time", optimizer = "glpk")
#>   hhidpn pair_id type
#> 1      1       1  trt
#> 2      2       1  all
#> 3      3      NA <NA>
#> 4      4       2  trt
#> 5      5       2  all

^{Created on 2021-02-09 by the reprex package (v1.0.0)}

[skent259]

This output is to be expected. The NA values indicate that the individual was not paired. This can easily happen when there is an odd number of ids, or when n_pairs is small. To show only those that are matched, you can pass the output to na.omit().