"exists" virtual track function without parameters now checks for exi…

…stance of any value.

Fixes emr_vtrack.create with func = "exists" on categorical track requires specification of values #120

NEWS.md

@@ -1,6 +1,7 @@
 # naryn 2.6.28 
 
 * Fix: `emr_track.mv` did not move track attributes. 
+* "exists" virtual track function without parameters now checks for existance of any value.
 
 # naryn 2.6.27
 

R/vtrack.R

@@ -276,8 +276,8 @@ emr_vtrack.create_from_name <- function(vtrack_name) {
 #' CATEGORICAL DATA SOURCE
 #'
 #' \tabular{lll}{ FUNC \tab PARAM \tab DESCRIPTION \cr value \tab vals/NULL
-#' \tab A source value or -1 if there is more than one. \cr exists \tab vals
-#' \tab 1 if any of the 'vals' exist otherwise 0. \cr sample \tab NULL \tab
+#' \tab A source value or -1 if there is more than one. \cr exists \tab vals/NULL
+#' \tab 1 if any of the 'vals' exist otherwise 0. NULL indicates the existence of any value\cr sample \tab NULL \tab
 #' Uniformly sampled source value. \cr sample.time \tab NULL \tab Time of the
 #' uniformly sampled source value. \cr frequent \tab vals/NULL \tab The most
 #' frequent source value or -1 if there is more than one value. \cr size \tab

src/NRTrackExpressionVars.cpp

@@ -198,9 +198,6 @@ void NRTrackExpressionVars::add_vtrack_var(const string &vtrack, SEXP rvtrack, b
             } else {
                 var.percentile = numeric_limits<double>::quiet_NaN();
 
-                if (ifunc == EMRTrack::EXISTS && isNull(rparams))
-                    verror("Virtual track %s: function %s requires an additional parameter", vtrack.c_str(), func.c_str());
-
                 if (is_categorical) {
                     if (!isNull(rparams)) {       
                         // params are a single NA value   

tests/testthat/test-vtrack.R

@@ -28,10 +28,13 @@ test_that("emr_vtrack works", {
     expect_equal(vt_name, "v1")
 })
 
-test_that("function exists requires an additional parameter", {
+test_that("function exists without additional parameters looks for all of them", {
     emr_vtrack.clear()
-    expect_error(emr_vtrack.create("v1", "track6", func = "exists"))
-    expect_error(emr_extract("v1"))
+    emr_vtrack.create("v1", "track6", func = "exists")
+    emr_vtrack.create("size", "track6", func = "size")
+    res <- emr_extract(c("v1", "size"), iterator = "track1") %>%
+        mutate(f = as.numeric(size > 0))
+    expect_equal(res$f, res$v1)
 })
 
 test_that("emr_vtrack works", {