From 64e619544d751d57660bfec884cb30eb9f212e2b Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Thu, 9 May 2024 17:43:48 -0700
Subject: [PATCH] add r version of as_sparse_double

---
 NAMESPACE               |  1 +
 R/coerce-vector.R       | 34 ++++++++++++++++++++++++++++++++++
 R/coerce.R              |  3 ++-
 _pkgdown.yml            |  1 +
 man/as_sparse_double.Rd | 23 +++++++++++++++++++++++
 5 files changed, 61 insertions(+), 1 deletion(-)
 create mode 100644 R/coerce-vector.R
 create mode 100644 man/as_sparse_double.Rd

diff --git a/NAMESPACE b/NAMESPACE
index 2f94f74..6adee0d 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,5 +1,6 @@
 # Generated by roxygen2: do not edit by hand
 
+export(as_sparse_double)
 export(coerce_to_sparse_data_frame)
 export(coerce_to_sparse_matrix)
 export(coerce_to_sparse_tibble)
diff --git a/R/coerce-vector.R b/R/coerce-vector.R
new file mode 100644
index 0000000..d078b09
--- /dev/null
+++ b/R/coerce-vector.R
@@ -0,0 +1,34 @@
+#' Coerce numeric vector to sparse double
+#' 
+#' @param x a numeric vector.
+#' @param default default value to use. Defaults to `0`.
+#'
+#' @examples
+#' x_dense <- c(3, 0, 2, 0, 0, 0, 4, 0, 0, 0)
+#' x_sparse <- as_sparse_double(x_dense)
+#' x_sparse
+#' 
+#' is_sparse_double(x_sparse) 
+#' @export
+as_sparse_double <- function(x, default = 0) {
+  if (is_sparse_double(x)) {
+    return(x)
+  }
+
+  if ((!is.numeric(x)) || (!is.vector(x))) {
+    cli::cli_abort(
+      "{.arg x} must be numeric vector, not {.obj_type_friendly {x}}."
+    )
+  }
+
+  check_number_decimal(default)
+
+  index <- which(x != default)
+
+  sparse_double(
+    values = x[index],
+    positions = index,
+    length = length(x),
+    default = default
+  )
+}
\ No newline at end of file
diff --git a/R/coerce.R b/R/coerce.R
index d20e0de..dd0e535 100644
--- a/R/coerce.R
+++ b/R/coerce.R
@@ -134,4 +134,5 @@ coerce_to_sparse_data_frame <- function(x) {
   
   names(res) <- colnames(x)
   res
-}
\ No newline at end of file
+}
+
diff --git a/_pkgdown.yml b/_pkgdown.yml
index 3505383..ee84f79 100644
--- a/_pkgdown.yml
+++ b/_pkgdown.yml
@@ -12,6 +12,7 @@ reference:
     - coerce_to_sparse_data_frame
     - coerce_to_sparse_matrix
     - coerce_to_sparse_tibble
+    - as_sparse_double
 
   - title: Helper Functions
     contents:
diff --git a/man/as_sparse_double.Rd b/man/as_sparse_double.Rd
new file mode 100644
index 0000000..f801216
--- /dev/null
+++ b/man/as_sparse_double.Rd
@@ -0,0 +1,23 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/coerce-vector.R
+\name{as_sparse_double}
+\alias{as_sparse_double}
+\title{Coerce numeric vector to sparse double}
+\usage{
+as_sparse_double(x, default = 0)
+}
+\arguments{
+\item{x}{a numeric vector.}
+
+\item{default}{default value to use. Defaults to \code{0}.}
+}
+\description{
+Coerce numeric vector to sparse double
+}
+\examples{
+x_dense <- c(3, 0, 2, 0, 0, 0, 4, 0, 0, 0)
+x_sparse <- as_sparse_double(x_dense)
+x_sparse
+
+is_sparse_double(x_sparse) 
+}