Fix: load failed when number of cores == 1 (#6)

* Fix: load failed when number of cores == 1
When the number of cores was 1, `round(parallel::detectCores() / 2)`
returned 0, which caused .onLoad to fail.
This fixes issue #4

* cran version 0.3.5

* added CRAN-SUBMISSION file

CRAN-SUBMISSION

@@ -1,3 +1,3 @@
-Version: 0.3.4
-Date: 2022-04-19 07:36:07 UTC
-SHA: 7069dbd5ba09a7199386c2691768f135fc407183
+Version: 0.3.5
+Date: 2022-08-27 20:16:58 UTC
+SHA: a22572c46cf5291dc364afc5415806ca30b5814e

DESCRIPTION

@@ -1,6 +1,6 @@
 Package: tglkmeans
 Title: Efficient Implementation of K-Means++ Algorithm
-Version: 0.3.4
+Version: 0.3.5
 Authors@R: 
     c(person(given = "Aviezer",
              family = "Lifshitz",
@@ -35,10 +35,11 @@ Suggests:
     knitr,
     rlang,
     rmarkdown,
-    testthat
+    testthat,
+    withr
 LinkingTo: 
     Rcpp
-VignetteBuilder:   
+VignetteBuilder: 
     knitr
 Encoding: UTF-8
 NeedsCompilation: yes

NEWS.md

@@ -1,10 +1,12 @@
-# tglkmeans (development version)
+# tglkmeans 0.3.5
 
 * Changed errors from cpp to 1 based indexing.
+* fix: loading the package failed on machines with a single core. 
 
 # tglkmeans 0.3.4 
 
 * First CRAN release.
+
 # tglkmeans 0.3.3
 
 * Set NA values to zeros in correlation matrix when reordering clusters 

R/misc.R

@@ -10,7 +10,7 @@
 #' }
 #' @export
 tglkmeans.set_parallel <- function(thread_num) {
-    if (1 == thread_num) {
+    if (thread_num <= 1) {
         options(tglkmeans.parallel = FALSE)
     } else {
         doFuture::registerDoFuture()

R/zzz.R

@@ -1,5 +1,5 @@
 .onLoad <- function(libname, pkgname) {
-    tglkmeans.set_parallel(round(parallel::detectCores() / 2))
+    tglkmeans.set_parallel(pmax(1, round(parallel::detectCores() / 2)))
     utils::suppressForeignCheck(c("clust", "new_clust", "true_clust", "intra_clust_order", "idx"))
     utils::globalVariables(c("clust", "new_clust", "true_clust", "intra_clust_order", "idx"))
 }

cran-comments.md

@@ -2,11 +2,7 @@
 
 0 errors | 0 warnings | 0 notes
 
-## DESCRIPTION changes
+# Fix
 
-* Added Weizmann Institute of Science as cph
-* Added references of the original algorithm to the description part. 
+* loading the package failed on machines with a single core. 
 
-## Regarding the use of cores in the examples
-
-* Added \donttest clause wrapping `tglmeans.set_parallel` examples section. The other examples work with a single core. 

tests/testthat/test-misc.R

@@ -10,12 +10,30 @@ test_that("onLoad does not fail", {
 })
 
 context("number of threads")
-test_that("parallel is turned off when number of threads is 1", {
-    tglkmeans.set_parallel(1)
-    expect_false(getOption("tglkmeans.parallel"))
+test_that("parallel is turned off when number of threads <= 1", {
+    withr::with_options(
+        list(tglkmeans.parallel = TRUE),
+        {
+            tglkmeans.set_parallel(1)
+            expect_false(getOption("tglkmeans.parallel"))
+        }
+    )
+
+    withr::with_options(
+        list(tglkmeans.parallel = TRUE),
+        {
+            tglkmeans.set_parallel(0)
+            expect_false(getOption("tglkmeans.parallel"))
+        }
+    )
 })
 
 test_that("parallel is turned on when number of threads is not 1", {
-    tglkmeans.set_parallel(2)
-    expect_true(getOption("tglkmeans.parallel"))
+    withr::with_options(
+        list(tglkmeans.parallel = FALSE),
+        {
+            tglkmeans.set_parallel(2)
+            expect_true(getOption("tglkmeans.parallel"))
+        }
+    )
 })