Merge pull request #55 from kevinushey/master

Make sure OBJECT bit appropriately set when melting (#50)
hadley · Jun 30, 2014 · 28e22a1 · 28e22a1
2 parents 379036a + 0658e7c
commit 28e22a1
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diff --git a/NAMESPACE b/NAMESPACE
@@ -1,4 +1,4 @@
-# Generated by roxygen2 (4.0.0): do not edit by hand
+# Generated by roxygen2 (4.0.1): do not edit by hand
 
 S3method(melt,array)
 S3method(melt,data.frame)

diff --git a/NEWS.md b/NEWS.md
@@ -1,5 +1,7 @@
 # Version 1.4.0.99
 
+* `melt.data.frame()` now properly sets the OBJECT bit on `value` variable generated if attributes are copied (for example, when multiple POSIXct columns are concatenated to generate the `value` variable) (#50)
+
 * `melt.data.frame()` no longer errors when `measure.vars` is `NULL` or empty.
   (#46)
 

diff --git a/man/add_margins.Rd b/man/add_margins.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{add_margins}
 \alias{add_margins}
 \title{Add margins to a data frame.}

diff --git a/man/cast.Rd b/man/cast.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{cast}
 \alias{acast}
 \alias{cast}

diff --git a/man/colsplit.Rd b/man/colsplit.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{colsplit}
 \alias{colsplit}
 \title{Split a vector into multiple columns}

diff --git a/man/french_fries.Rd b/man/french_fries.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \docType{data}
 \name{french_fries}
 \alias{french_fries}

diff --git a/man/guess_value.Rd b/man/guess_value.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{guess_value}
 \alias{guess_value}
 \title{Guess name of value column}

diff --git a/man/margins.Rd b/man/margins.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{margins}
 \alias{margins}
 \title{Figure out margining variables.}

diff --git a/man/melt.Rd b/man/melt.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt}
 \alias{melt}
 \title{Convert an object into a molten data frame.}

diff --git a/man/melt.array.Rd b/man/melt.array.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt.array}
 \alias{melt.array}
 \alias{melt.matrix}

diff --git a/man/melt.data.frame.Rd b/man/melt.data.frame.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt.data.frame}
 \alias{melt.data.frame}
 \title{Melt a data frame into form suitable for easy casting.}

diff --git a/man/melt.default.Rd b/man/melt.default.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt.default}
 \alias{melt.default}
 \title{Melt a vector.

diff --git a/man/melt.list.Rd b/man/melt.list.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt.list}
 \alias{melt.list}
 \title{Melt a list by recursively melting each component.}

diff --git a/man/melt_check.Rd b/man/melt_check.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{melt_check}
 \alias{melt_check}
 \title{Check that input variables to melt are appropriate.}

diff --git a/man/parse_formula.Rd b/man/parse_formula.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{parse_formula}
 \alias{parse_formula}
 \title{Parse casting formulae.}

diff --git a/man/recast.Rd b/man/recast.Rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \name{recast}
 \alias{recast}
 \title{Recast: melt and cast in a single step}

diff --git a/man/smiths.rd b/man/smiths.rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \docType{data}
 \name{smiths}
 \alias{smiths}

diff --git a/man/tips.rd b/man/tips.rd
@@ -1,4 +1,4 @@
-% Generated by roxygen2 (4.0.0): do not edit by hand
+% Generated by roxygen2 (4.0.1): do not edit by hand
 \docType{data}
 \name{tips}
 \alias{tips}

diff --git a/src/melt.cpp b/src/melt.cpp
@@ -267,12 +267,11 @@ List melt_dataframe(const DataFrame& data,
   output[n_id + 1] = concatenate(data, measure_ind, factorsAsStrings);
   if (!Rf_isNull(measure_attributes)) {
     SET_ATTRIB(output[n_id + 1], measure_attributes);
-  }
-
-  // Set the object bit explicitly to make sure that the 'value' is properly
-  // interpreted as a factor
-  if (valueAsFactor) {
-    SET_OBJECT(output[n_id + 1], 1);
+    // we also need to make sure the OBJECT bit is set for other 'object' types
+    // see: http://stackoverflow.com/questions/24059460/melt-data-frame-changes-behavior-how-posixct-columns-are-printed
+    // if we've entered this code block, the measure_attributes has been
+    // populated because all value variables have identical attributes
+    SET_OBJECT(output[n_id + 1], OBJECT(data[measure_ind[0]]));
   }
 
   // Make the List more data.frame like

diff --git a/tests/testthat/test-melt.r b/tests/testthat/test-melt.r
@@ -183,3 +183,18 @@ test_that("melt.data.frame behaves when there are no measure variables", {
   expect_identical(df["x"], m)
 
 })
+
+test_that("melt.data.frame preserves OBJECT bit on e.g. POSIXct", {
+  t.wide <- data.frame(product=letters[1:5],
+                       result=c(2, 4, 0, 0, 1),
+                       t1=as.POSIXct("2014-05-26") + seq(0, 10800, length.out=5),
+                       t2=as.POSIXct("2014-05-27") + seq(0, 10800, length.out=5),
+                       t3=as.POSIXct("2014-05-28") + seq(0, 10800, length.out=5))
+
+  library(reshape2)
+  object_bit_set <- function(x) {
+    grepl("\\[OBJ", capture.output(.Internal(inspect(x)))[1])
+  }
+  t.long <- melt(t.wide, measure.vars=c("t1", "t2", "t3"), value.name="time")
+  expect_true(object_bit_set(t.long$time))
+})