make apslit conditional in vignette and tests

R/pudding.R

@@ -29,10 +29,10 @@
 #' # ties: use an array list (easier with R >= 3.6.0)
 #' if (getRversion() < "3.6.0"){
 #'   n <- nrow(pudding)
-#'   ties <- data.frame(Winner = array(split(pudding[, c("i", "j")], 1:n, n)),
+#'   ties <- data.frame(Winner = array(split(pudding[c("i", "j")], 1:n), n),
 #'                      Loser = rep(NA, 15))
 #' } else {
-#'   ties <- data.frame(Winner = asplit(pudding[, c("i", "j")], 1),
+#'   ties <- data.frame(Winner = asplit(pudding[c("i", "j")], 1),
 #'                      Loser = rep(NA, 15))
 #' }
 #' head(ties, 2)

cran-comments.md

@@ -1,6 +1,10 @@
 ## Comments
 
-This submission is mainly to fix a bug in the vcov method that causes NA values for a particular parameterization. Some other minor fixes and improvements have been made at the same time.
+This submission:
+  - uses alternative to base::asplit in R < 3.6.0 (to fix errors on CRAN)
+  - fixes bug in vcov method that causes NA values for a particular parameterization. 
+
+Some other minor fixes and improvements have been made at the same time.
 
 ## Test environments
 
@@ -10,10 +14,13 @@ This submission is mainly to fix a bug in the vcov method that causes NA values
 4. (R-hub) Windows Server 2008 R2 SP1, R-devel, 32/64 bit
 5. (R-hub) macOS 10.11 El Capitan, R-release
 6. (Win-builder) Windows Server 2008 (64-bit), R-devel
+7. (Win-builder) Windows Server 2008 (64-bit), R-oldrelease
 
 ### Check results
 
-Check 3, 4 & 6 returns a note regarding URLs/DOIs. This is a false alarm: all the links redirect to valid pages on jstor.
+Checks 3, 4, 6  & 7 return a note regarding URLs/DOIs. This is a false alarm: all the links redirect to valid pages on jstor.org.
+
+Check 7 gives an additional note: "no visible global function definition for 'asplit'". However, the code conditions on R version, so asplit is only called if R >= 3.6.0. This conditional execution is validated by the fact that the examples and tests do not fail on this installation, which has R-3.5.3.
 
 ## revdepcheck results
 

tests/testthat/test-vcov.R

@@ -152,8 +152,14 @@ test_that("vcov.PlackettLuce works w/ different ref [pudding]", {
     # create orderings for each set of paired comparisons
     i_wins <- data.frame(Winner = pudding$i, Loser = pudding$j)
     j_wins <- data.frame(Winner = pudding$j, Loser = pudding$i)
-    ties <- data.frame(Winner = asplit(pudding[, c("i", "j")], 1),
-                       Loser = rep(NA, 15))
+    if (getRversion() < "3.6.0"){
+        n <- nrow(pudding)
+        ties <- data.frame(Winner = array(split(pudding[c("i", "j")], 1:n), n),
+                           Loser = rep(NA, 15))
+    } else {
+        ties <- data.frame(Winner = asplit(pudding[c("i", "j")], 1),
+                           Loser = rep(NA, 15))
+    }
     # convert to rankings
     R <- as.rankings(rbind(i_wins, j_wins, ties),
                      input = "orderings")

vignettes/Overview.Rmd

@@ -430,13 +430,19 @@ corresponding to the wins for item $i$, the wins for item $j$ and the ties:
 ```{r}
 i_wins <- data.frame(Winner = pudding$i, Loser = pudding$j)
 j_wins <- data.frame(Winner = pudding$j, Loser = pudding$i)
-ties <- data.frame(Winner = asplit(pudding[, c("i", "j")], 1),
-                   Loser = rep(NA, 15))
+if (getRversion() < "3.6.0"){
+  n <- nrow(pudding)
+  ties <- data.frame(Winner = array(split(pudding[c("i", "j")], 1:n), n),
+                     Loser = rep(NA, 15))
+} else {
+  ties <- data.frame(Winner = asplit(pudding[c("i", "j")], 1),
+                     Loser = rep(NA, 15))
+}
 head(ties, 2)
 ```
-In the last case, the base R function `asplit` is used to split the `i` and `j` 
-columns of `pudding` by row, giving a vector of items that we can specify as 
-the winner, while the loser is missing.
+In the last case, we split the `i` and `j` columns of `pudding` by row, using 
+the base R function `asplit`, if available. For each pair, this gives a vector 
+of items that we can specify as the winner, while the loser is missing.
 
 Now the `as.rankings()` function from **PlackettLuce** can be used to convert 
 the combined orderings to an object of class `"rankings"`.