From 4584a9b3b86be70140c24037d43c2950ce44eca3 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 22 May 2024 21:36:40 -0700
Subject: [PATCH 01/16] let fit_xy() take dgCMatrix input

---
 R/convert_data.R | 6 +++++-
 R/fit.R          | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/R/convert_data.R b/R/convert_data.R
index 519aec9e3..2a573961a 100644
--- a/R/convert_data.R
+++ b/R/convert_data.R
@@ -374,7 +374,11 @@ maybe_matrix <- function(x) {
                         "converted to numeric matrix: {non_num_cols}.")
       rlang::abort(msg)
     }
-    x <- as.matrix(x)
+    if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {
+      x <- sparsevctrs::coerce_to_sparse_matrix(x)
+    } else {
+      x <- as.matrix(x)
+    }
   }
   # leave alone if matrix or sparse matrix
   x
diff --git a/R/fit.R b/R/fit.R
index 288fc64a2..3553b96f4 100644
--- a/R/fit.R
+++ b/R/fit.R
@@ -275,6 +275,10 @@ fit_xy.model_spec <-
       }
     }
 
+    if (allow_sparse(object) && methods::is(x, "sparseMatrix")) {
+      x <- sparsevctrs::coerce_to_sparse_data_frame(x)
+    }
+
     cl <- match.call(expand.dots = TRUE)
     eval_env <- rlang::env()
     eval_env$x <- x
@@ -387,7 +391,7 @@ inher <- function(x, cls, cl) {
 
 check_interface <- function(formula, data, cl, model) {
   inher(formula, "formula", cl)
-  inher(data, c("data.frame", "tbl_spark"), cl)
+  inher(data, c("data.frame", "dgCMatrix", "tbl_spark"), cl)
 
   # Determine the `fit()` interface
   form_interface <- !is.null(formula) & !is.null(data)

From d1d4df4271b49f183f78180f43fccfad8b9801dd Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 22 May 2024 21:43:24 -0700
Subject: [PATCH 02/16] only turn into sparse data frame if model allow sparse
 data

---
 R/fit.R | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/R/fit.R b/R/fit.R
index 3553b96f4..1d115b7aa 100644
--- a/R/fit.R
+++ b/R/fit.R
@@ -275,8 +275,16 @@ fit_xy.model_spec <-
       }
     }
 
-    if (allow_sparse(object) && methods::is(x, "sparseMatrix")) {
-      x <- sparsevctrs::coerce_to_sparse_data_frame(x)
+    if (methods::is(x, "sparseMatrix")) {
+      if (allow_sparse(object)) {
+        x <- sparsevctrs::coerce_to_sparse_data_frame(x)
+      } else {
+        cli::cli_warn(c(
+          "!" = "{.arg x} is a sparse matrix, but model doesn't accept that.",
+          "i" = "Converted {.arg x} to data.frame."
+        ))
+        x <- as.data.frame(x)
+      }
     }
 
     cl <- match.call(expand.dots = TRUE)

From bbe0732a9215d074611665de527088759235946d Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 22 May 2024 21:45:33 -0700
Subject: [PATCH 03/16] add sparsevctrs to imports

---
 DESCRIPTION | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index bfa80fed1..c605a7c8d 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -32,6 +32,7 @@ Imports:
     prettyunits,
     purrr (>= 1.0.0),
     rlang (>= 1.1.0),
+    sparsevctrs (>= 0.1.0),
     stats,
     tibble (>= 2.1.1),
     tidyr (>= 1.3.0),
@@ -78,5 +79,6 @@ Encoding: UTF-8
 LazyData: true
 Roxygen: list(markdown = TRUE)
 Remotes:  
-    tidymodels/hardhat
+    tidymodels/hardhat,
+    r-lib/sparsevctrs
 RoxygenNote: 7.3.1

From 6e2fb0096b3f1eaf7ab6200cd4378e51a44fa11e Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 12 Jun 2024 22:04:42 -0700
Subject: [PATCH 04/16] delete failing test

---
 tests/testthat/test-rand_forest_ranger.R | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/tests/testthat/test-rand_forest_ranger.R b/tests/testthat/test-rand_forest_ranger.R
index b94db7e7f..a40eb4780 100644
--- a/tests/testthat/test-rand_forest_ranger.R
+++ b/tests/testthat/test-rand_forest_ranger.R
@@ -475,16 +475,6 @@ test_that('ranger and sparse matrices', {
 
   expect_equal(extract_fit_engine(from_df), extract_fit_engine(from_mat))
   expect_equal(extract_fit_engine(from_df), extract_fit_engine(from_sparse))
-
-  rf_spec <-
-    rand_forest(trees = 10) %>%
-    set_engine("randomForest", seed = 2) %>%
-    set_mode("regression")
-  expect_error(
-    rf_spec %>% fit_xy(mtcar_smat, mtcars$mpg),
-    "Sparse matrices not supported"
-  )
-
 })
 
 

From 44f2f8189ba52bfbf7407967c52adc0a73df3a2b Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 12 Jun 2024 22:04:59 -0700
Subject: [PATCH 05/16] add sparse_hotel_rates() helper function

---
 tests/testthat/helper-objects.R | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/tests/testthat/helper-objects.R b/tests/testthat/helper-objects.R
index a9297a65a..b00c3c2c8 100644
--- a/tests/testthat/helper-objects.R
+++ b/tests/testthat/helper-objects.R
@@ -24,3 +24,30 @@ is_tf_ok <- function() {
   }
   res
 }
+
+# ------------------------------------------------------------------------------
+# For sparse tibble testing
+
+sparse_hotel_rates <- function() {
+  # 99.2 sparsity
+  hotel_rates <- modeldata::hotel_rates
+
+  prefix_colnames <- function(x, prefix) {
+    colnames(x) <- paste(colnames(x), prefix, sep = "_")
+    x
+  }
+
+  dummies_country <- hardhat::fct_encode_one_hot(hotel_rates$country)
+  dummies_company <- hardhat::fct_encode_one_hot(hotel_rates$company)
+  dummies_agent <- hardhat::fct_encode_one_hot(hotel_rates$agent)
+
+  res <- dplyr::bind_cols(
+    hotel_rates["avg_price_per_room"],
+    prefix_colnames(dummies_country, "country"),
+    prefix_colnames(dummies_company, "company"),
+    prefix_colnames(dummies_agent, "agent")
+  )
+
+  res <- as.matrix(res)
+  Matrix::Matrix(res, sparse = TRUE)
+}
\ No newline at end of file

From fb14d889f8915b033777609b47a604b87c8800c1 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 12 Jun 2024 22:30:21 -0700
Subject: [PATCH 06/16] add methods to suggests

---
 DESCRIPTION | 1 +
 1 file changed, 1 insertion(+)

diff --git a/DESCRIPTION b/DESCRIPTION
index c605a7c8d..984f37adb 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -53,6 +53,7 @@ Suggests:
     LiblineaR,
     MASS,
     Matrix,
+    methods,
     mgcv,
     modeldata,
     nlme,

From 28420f6cb55f0c6bcd29bfe9c89bd9e809324683 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Fri, 28 Jun 2024 18:30:18 -0700
Subject: [PATCH 07/16] refactor sparevctrs functions out

---
 R/convert_data.R | 15 ++++++++++-----
 R/fit.R          | 12 +-----------
 R/sparsevctrs.R  | 14 ++++++++++++++
 3 files changed, 25 insertions(+), 16 deletions(-)
 create mode 100644 R/sparsevctrs.R

diff --git a/R/convert_data.R b/R/convert_data.R
index 2a573961a..64c93e02c 100644
--- a/R/convert_data.R
+++ b/R/convert_data.R
@@ -374,16 +374,21 @@ maybe_matrix <- function(x) {
                         "converted to numeric matrix: {non_num_cols}.")
       rlang::abort(msg)
     }
-    if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {
-      x <- sparsevctrs::coerce_to_sparse_matrix(x)
-    } else {
-      x <- as.matrix(x)
-    }
+    x <- maybe_sparse_matrix(x)
   }
   # leave alone if matrix or sparse matrix
   x
 }
 
+maybe_sparse_matrix <- function(x) {
+  if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {
+    res <- sparsevctrs::coerce_to_sparse_matrix(x)
+  } else {
+    res <- as.matrix(x)
+  }
+  res
+}
+
 #' @rdname maybe_matrix
 #' @export
 maybe_data_frame <- function(x) {
diff --git a/R/fit.R b/R/fit.R
index 1d115b7aa..1345a95af 100644
--- a/R/fit.R
+++ b/R/fit.R
@@ -275,17 +275,7 @@ fit_xy.model_spec <-
       }
     }
 
-    if (methods::is(x, "sparseMatrix")) {
-      if (allow_sparse(object)) {
-        x <- sparsevctrs::coerce_to_sparse_data_frame(x)
-      } else {
-        cli::cli_warn(c(
-          "!" = "{.arg x} is a sparse matrix, but model doesn't accept that.",
-          "i" = "Converted {.arg x} to data.frame."
-        ))
-        x <- as.data.frame(x)
-      }
-    }
+    x <- to_sparse_data_frame(x, object)
 
     cl <- match.call(expand.dots = TRUE)
     eval_env <- rlang::env()
diff --git a/R/sparsevctrs.R b/R/sparsevctrs.R
new file mode 100644
index 000000000..107c3932e
--- /dev/null
+++ b/R/sparsevctrs.R
@@ -0,0 +1,14 @@
+to_sparse_data_frame <- function(x, object) {
+  if (methods::is(x, "sparseMatrix")) {
+    if (allow_sparse(object)) {
+      x <- sparsevctrs::coerce_to_sparse_data_frame(x)
+    } else {
+      cli::cli_warn(c(
+        "!" = "{.arg x} is a sparse matrix, but model doesn't accept that.",
+        "i" = "Converted {.arg x} to data.frame."
+      ))
+      x <- as.data.frame(x)
+    }
+  }
+  x
+}
\ No newline at end of file

From fddd5907dfce0087870d3463edd77327dcbaa8c3 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Fri, 28 Jun 2024 18:30:25 -0700
Subject: [PATCH 08/16] test sparsevctrs functions in use

---
 tests/testthat/_snaps/sparsevctrs.md | 57 ++++++++++++++++++++
 tests/testthat/test-sparsevctrs.R    | 81 ++++++++++++++++++++++++++++
 2 files changed, 138 insertions(+)
 create mode 100644 tests/testthat/_snaps/sparsevctrs.md
 create mode 100644 tests/testthat/test-sparsevctrs.R

diff --git a/tests/testthat/_snaps/sparsevctrs.md b/tests/testthat/_snaps/sparsevctrs.md
new file mode 100644
index 000000000..484030f77
--- /dev/null
+++ b/tests/testthat/_snaps/sparsevctrs.md
@@ -0,0 +1,57 @@
+# to_sparse_data_frame() is used correctly
+
+    Code
+      fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+    Condition
+      Error in `to_sparse_data_frame()`:
+      ! x is not sparse
+
+---
+
+    Code
+      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    Condition
+      Error in `to_sparse_data_frame()`:
+      ! x is spare, and sparse is not allowed
+
+---
+
+    Code
+      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    Condition
+      Error in `to_sparse_data_frame()`:
+      ! x is spare, and sparse is allowed
+
+# maybe_sparse_matrix() is used correctly
+
+    Code
+      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    Condition
+      Error in `maybe_sparse_matrix()`:
+      ! sparse vectors detected
+
+---
+
+    Code
+      fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+    Condition
+      Error in `maybe_sparse_matrix()`:
+      ! no sparse vectors detected
+
+---
+
+    Code
+      fit_xy(lm_spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
+    Condition
+      Error in `maybe_sparse_matrix()`:
+      ! no sparse vectors detected
+
+---
+
+    Code
+      fit_xy(lm_spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(
+        mtcars)[, 1])
+    Condition
+      Error in `maybe_sparse_matrix()`:
+      ! no sparse vectors detected
+
diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
new file mode 100644
index 000000000..bcfadf738
--- /dev/null
+++ b/tests/testthat/test-sparsevctrs.R
@@ -0,0 +1,81 @@
+test_that("sparse matrices can be passed to `fit_xy()", {
+  hotel_data <- sparse_hotel_rates()
+
+  lm_spec <- linear_reg(penalty = 0) %>%
+    set_engine("glmnet")
+
+  expect_no_error(
+    lm_fit <- fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+  )
+})
+
+test_that("to_sparse_data_frame() is used correctly", {
+  local_mocked_bindings(
+    to_sparse_data_frame = function(x, object) {
+      if (methods::is(x, "sparseMatrix")) {
+        if (allow_sparse(object)) {
+          stop("x is spare, and sparse is allowed")
+        } else {
+          stop("x is spare, and sparse is not allowed")
+        }
+      }
+      stop("x is not sparse")
+    }
+  )
+
+  hotel_data <- sparse_hotel_rates()
+
+  lm_spec <- linear_reg(penalty = 0) %>%
+    set_engine("lm")
+
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+  )
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+  )
+  
+  lm_spec <- linear_reg(penalty = 0) %>%
+    set_engine("glmnet")
+
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+  )
+})
+
+test_that("maybe_sparse_matrix() is used correctly", {
+  local_mocked_bindings(
+    maybe_sparse_matrix = function(x) {
+      if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {
+        stop("sparse vectors detected")
+      } else {
+        stop("no sparse vectors detected")
+      }
+    }
+  )
+
+  hotel_data <- sparse_hotel_rates()
+
+  lm_spec <- linear_reg(penalty = 0) %>%
+    set_engine("glmnet")
+
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+  )
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+  )
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
+  )
+  expect_snapshot(
+    error = TRUE,
+    fit_xy(lm_spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(mtcars)[, 1])
+  )
+})

From 2b8f56e47bdf9a3768b99e96cfaf5adb3a6c506e Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Fri, 28 Jun 2024 19:43:20 -0700
Subject: [PATCH 09/16] don't use glmnet in sparsevctrs tests

---
 tests/testthat/_snaps/sparsevctrs.md | 16 ++++++------
 tests/testthat/test-sparsevctrs.R    | 39 +++++++++++++++++-----------
 2 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/tests/testthat/_snaps/sparsevctrs.md b/tests/testthat/_snaps/sparsevctrs.md
index 484030f77..abbf43efb 100644
--- a/tests/testthat/_snaps/sparsevctrs.md
+++ b/tests/testthat/_snaps/sparsevctrs.md
@@ -1,7 +1,7 @@
 # to_sparse_data_frame() is used correctly
 
     Code
-      fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+      fit_xy(spec, x = mtcars[, -1], y = mtcars[, 1])
     Condition
       Error in `to_sparse_data_frame()`:
       ! x is not sparse
@@ -9,7 +9,7 @@
 ---
 
     Code
-      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+      fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
     Condition
       Error in `to_sparse_data_frame()`:
       ! x is spare, and sparse is not allowed
@@ -17,7 +17,7 @@
 ---
 
     Code
-      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+      fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
     Condition
       Error in `to_sparse_data_frame()`:
       ! x is spare, and sparse is allowed
@@ -25,7 +25,7 @@
 # maybe_sparse_matrix() is used correctly
 
     Code
-      fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+      fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
     Condition
       Error in `maybe_sparse_matrix()`:
       ! sparse vectors detected
@@ -33,7 +33,7 @@
 ---
 
     Code
-      fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+      fit_xy(spec, x = mtcars[, -1], y = mtcars[, 1])
     Condition
       Error in `maybe_sparse_matrix()`:
       ! no sparse vectors detected
@@ -41,7 +41,7 @@
 ---
 
     Code
-      fit_xy(lm_spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
+      fit_xy(spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
     Condition
       Error in `maybe_sparse_matrix()`:
       ! no sparse vectors detected
@@ -49,8 +49,8 @@
 ---
 
     Code
-      fit_xy(lm_spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(
-        mtcars)[, 1])
+      fit_xy(spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(mtcars)[,
+        1])
     Condition
       Error in `maybe_sparse_matrix()`:
       ! no sparse vectors detected
diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index bcfadf738..e5d5e0511 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -1,15 +1,20 @@
 test_that("sparse matrices can be passed to `fit_xy()", {
+  skip_if_not_installed("LiblineaR")
+
   hotel_data <- sparse_hotel_rates()
 
-  lm_spec <- linear_reg(penalty = 0) %>%
-    set_engine("glmnet")
+  spec <- svm_linear() %>%
+    set_mode("regression") %>%
+    set_engine("LiblineaR")
 
   expect_no_error(
-    lm_fit <- fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    lm_fit <- fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
 })
 
 test_that("to_sparse_data_frame() is used correctly", {
+  skip_if_not_installed("LiblineaR")
+  
   local_mocked_bindings(
     to_sparse_data_frame = function(x, object) {
       if (methods::is(x, "sparseMatrix")) {
@@ -25,28 +30,31 @@ test_that("to_sparse_data_frame() is used correctly", {
 
   hotel_data <- sparse_hotel_rates()
 
-  lm_spec <- linear_reg(penalty = 0) %>%
+  spec <- linear_reg() %>%
     set_engine("lm")
 
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+    fit_xy(spec, x = mtcars[, -1], y = mtcars[, 1])
   )
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
   
-  lm_spec <- linear_reg(penalty = 0) %>%
-    set_engine("glmnet")
+  spec <- svm_linear() %>%
+    set_mode("regression") %>%
+    set_engine("LiblineaR")
 
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
 })
 
 test_that("maybe_sparse_matrix() is used correctly", {
+  skip_if_not_installed("LiblineaR")
+  
   local_mocked_bindings(
     maybe_sparse_matrix = function(x) {
       if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {
@@ -59,23 +67,24 @@ test_that("maybe_sparse_matrix() is used correctly", {
 
   hotel_data <- sparse_hotel_rates()
 
-  lm_spec <- linear_reg(penalty = 0) %>%
-    set_engine("glmnet")
+  spec <- svm_linear() %>%
+    set_mode("regression") %>%
+    set_engine("LiblineaR")
 
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = hotel_data[, -1], y = hotel_data[, 1])
+    fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = mtcars[, -1], y = mtcars[, 1])
+    fit_xy(spec, x = mtcars[, -1], y = mtcars[, 1])
   )
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
+    fit_xy(spec, x = as.data.frame(mtcars)[, -1], y = as.data.frame(mtcars)[, 1])
   )
   expect_snapshot(
     error = TRUE,
-    fit_xy(lm_spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(mtcars)[, 1])
+    fit_xy(spec, x = tibble::as_tibble(mtcars)[, -1], y = tibble::as_tibble(mtcars)[, 1])
   )
 })

From ae90e84365697c391f550988c190b745a5e9a771 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Fri, 28 Jun 2024 19:47:24 -0700
Subject: [PATCH 10/16] set minimum sparsevctrs version

---
 DESCRIPTION | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/DESCRIPTION b/DESCRIPTION
index 984f37adb..3f4587d32 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -32,7 +32,7 @@ Imports:
     prettyunits,
     purrr (>= 1.0.0),
     rlang (>= 1.1.0),
-    sparsevctrs (>= 0.1.0),
+    sparsevctrs (>= 0.1.0.9000),
     stats,
     tibble (>= 2.1.1),
     tidyr (>= 1.3.0),

From 124f925b928ebf7b687c33e17e700fdfca17f5fd Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Sat, 29 Jun 2024 15:39:30 -0700
Subject: [PATCH 11/16] trigger warning in to_sparse_data_frame()

---
 R/sparsevctrs.R                      | 2 +-
 tests/testthat/_snaps/sparsevctrs.md | 9 +++++++++
 tests/testthat/test-sparsevctrs.R    | 8 ++++++++
 3 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/R/sparsevctrs.R b/R/sparsevctrs.R
index 107c3932e..58d866396 100644
--- a/R/sparsevctrs.R
+++ b/R/sparsevctrs.R
@@ -7,7 +7,7 @@ to_sparse_data_frame <- function(x, object) {
         "!" = "{.arg x} is a sparse matrix, but model doesn't accept that.",
         "i" = "Converted {.arg x} to data.frame."
       ))
-      x <- as.data.frame(x)
+      x <- as.data.frame(as.matrix(x))
     }
   }
   x
diff --git a/tests/testthat/_snaps/sparsevctrs.md b/tests/testthat/_snaps/sparsevctrs.md
index abbf43efb..100e33895 100644
--- a/tests/testthat/_snaps/sparsevctrs.md
+++ b/tests/testthat/_snaps/sparsevctrs.md
@@ -1,3 +1,12 @@
+# sparse matrices can be passed to `fit_xy()
+
+    Code
+      lm_fit <- fit_xy(spec, x = hotel_data[1:100, -1], y = hotel_data[1:100, 1])
+    Condition
+      Warning:
+      ! `x` is a sparse matrix, but model doesn't accept that.
+      i Converted `x` to data.frame.
+
 # to_sparse_data_frame() is used correctly
 
     Code
diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index e5d5e0511..713cde557 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -10,6 +10,14 @@ test_that("sparse matrices can be passed to `fit_xy()", {
   expect_no_error(
     lm_fit <- fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
+
+  spec <- linear_reg() %>%
+    set_mode("regression") %>%
+    set_engine("lm")
+
+  expect_snapshot(
+    lm_fit <- fit_xy(spec, x = hotel_data[1:100, -1], y = hotel_data[1:100, 1])
+  )
 })
 
 test_that("to_sparse_data_frame() is used correctly", {

From 7718d679d3aa240f8a6abb4d948288581184caf6 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Tue, 27 Aug 2024 16:45:39 -0700
Subject: [PATCH 12/16] document a little more for sparse matrix input

---
 NEWS.md                         | 1 +
 R/fit.R                         | 5 +++++
 man/fit.Rd                      | 4 ++++
 tests/testthat/helper-objects.R | 2 +-
 4 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/NEWS.md b/NEWS.md
index c51afb0e7..b5309b4f1 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,6 @@
 # parsnip (development version)
 
+* `fit_xy()` can now take dgCMatrix input for `x` argument (#1121).
 
 * `fit_xy()` currently raises an error for `gen_additive_mod()` model specifications as the default engine (`"mgcv"`) specifies smoothing terms in model formulas. However, some engines specify smooths via additional arguments, in which case the restriction on `fit_xy()` is excessive. parsnip will now only raise an error when fitting a `gen_additive_mod()` with `fit_xy()` when using the `"mgcv"` engine (#775).
 
diff --git a/R/fit.R b/R/fit.R
index 58c06d4ac..0cfe7f5b0 100644
--- a/R/fit.R
+++ b/R/fit.R
@@ -55,6 +55,11 @@
 #' a "reverse Kaplan-Meier" curve that models the probability of censoring. This
 #' may be used later to compute inverse probability censoring weights for
 #' performance measures.
+#' 
+#' Sparse data is supported, with the use of the `x` argument in `fit_xy()`. See
+#' `allow_sparse_x` column of [parsnip::get_encoding()] for sparse input 
+#' compatibility.
+#' 
 #' @examplesIf !parsnip:::is_cran_check()
 #' # Although `glm()` only has a formula interface, different
 #' # methods for specifying the model can be used
diff --git a/man/fit.Rd b/man/fit.Rd
index b4c16f278..332d993bc 100644
--- a/man/fit.Rd
+++ b/man/fit.Rd
@@ -103,6 +103,10 @@ executed and saved in the parsnip object. The \code{censor_probs} element contai
 a "reverse Kaplan-Meier" curve that models the probability of censoring. This
 may be used later to compute inverse probability censoring weights for
 performance measures.
+
+Sparse data is supported, with the use of the \code{x} argument in \code{fit_xy()}. See
+\code{allow_sparse_x} column of \code{\link[=get_encoding]{get_encoding()}} for sparse input
+compatibility.
 }
 \examples{
 \dontshow{if (!parsnip:::is_cran_check()) (if (getRversion() >= "3.4") withAutoprint else force)(\{ # examplesIf}
diff --git a/tests/testthat/helper-objects.R b/tests/testthat/helper-objects.R
index b00c3c2c8..f2e24a353 100644
--- a/tests/testthat/helper-objects.R
+++ b/tests/testthat/helper-objects.R
@@ -50,4 +50,4 @@ sparse_hotel_rates <- function() {
 
   res <- as.matrix(res)
   Matrix::Matrix(res, sparse = TRUE)
-}
\ No newline at end of file
+}

From f2faed9778428262d421afd1c51661ace39ba302 Mon Sep 17 00:00:00 2001
From: topepo <mxkuhn@gmail.com>
Date: Wed, 28 Aug 2024 10:10:37 -0400
Subject: [PATCH 13/16] convert warning to error

---
 R/sparsevctrs.R                      | 10 ++++------
 tests/testthat/_snaps/sparsevctrs.md |  5 ++---
 tests/testthat/test-sparsevctrs.R    |  9 +++++----
 3 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/R/sparsevctrs.R b/R/sparsevctrs.R
index 58d866396..a7a65cf45 100644
--- a/R/sparsevctrs.R
+++ b/R/sparsevctrs.R
@@ -3,12 +3,10 @@ to_sparse_data_frame <- function(x, object) {
     if (allow_sparse(object)) {
       x <- sparsevctrs::coerce_to_sparse_data_frame(x)
     } else {
-      cli::cli_warn(c(
-        "!" = "{.arg x} is a sparse matrix, but model doesn't accept that.",
-        "i" = "Converted {.arg x} to data.frame."
-      ))
-      x <- as.data.frame(as.matrix(x))
+      cli::cli_abort(
+      "{.arg x} is a sparse matrix, but {.fn {class(object)[1]}} with
+       engine {.code {object$engine}} doesn't accept that.")
     }
   }
   x
-}
\ No newline at end of file
+}
diff --git a/tests/testthat/_snaps/sparsevctrs.md b/tests/testthat/_snaps/sparsevctrs.md
index 100e33895..02cb9611b 100644
--- a/tests/testthat/_snaps/sparsevctrs.md
+++ b/tests/testthat/_snaps/sparsevctrs.md
@@ -3,9 +3,8 @@
     Code
       lm_fit <- fit_xy(spec, x = hotel_data[1:100, -1], y = hotel_data[1:100, 1])
     Condition
-      Warning:
-      ! `x` is a sparse matrix, but model doesn't accept that.
-      i Converted `x` to data.frame.
+      Error in `to_sparse_data_frame()`:
+      ! `x` is a sparse matrix, but `linear_reg()` with engine `lm` doesn't accept that.
 
 # to_sparse_data_frame() is used correctly
 
diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index 713cde557..7e6a904bb 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -16,13 +16,14 @@ test_that("sparse matrices can be passed to `fit_xy()", {
     set_engine("lm")
 
   expect_snapshot(
-    lm_fit <- fit_xy(spec, x = hotel_data[1:100, -1], y = hotel_data[1:100, 1])
+    lm_fit <- fit_xy(spec, x = hotel_data[1:100, -1], y = hotel_data[1:100, 1]),
+    error = TRUE
   )
 })
 
 test_that("to_sparse_data_frame() is used correctly", {
   skip_if_not_installed("LiblineaR")
-  
+
   local_mocked_bindings(
     to_sparse_data_frame = function(x, object) {
       if (methods::is(x, "sparseMatrix")) {
@@ -49,7 +50,7 @@ test_that("to_sparse_data_frame() is used correctly", {
     error = TRUE,
     fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
-  
+
   spec <- svm_linear() %>%
     set_mode("regression") %>%
     set_engine("LiblineaR")
@@ -62,7 +63,7 @@ test_that("to_sparse_data_frame() is used correctly", {
 
 test_that("maybe_sparse_matrix() is used correctly", {
   skip_if_not_installed("LiblineaR")
-  
+
   local_mocked_bindings(
     maybe_sparse_matrix = function(x) {
       if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {

From 616b548a6bbbedd4ece0b0e8213bb3684ae41400 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 28 Aug 2024 09:11:38 -0700
Subject: [PATCH 14/16] use less noisy model/engine for sparsevctrs tests

---
 tests/testthat/test-sparsevctrs.R | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index 713cde557..8f112eb78 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -1,11 +1,11 @@
 test_that("sparse matrices can be passed to `fit_xy()", {
-  skip_if_not_installed("LiblineaR")
+  skip_if_not_installed("xgboost")
 
   hotel_data <- sparse_hotel_rates()
 
-  spec <- svm_linear() %>%
+  spec <- boost_tree() %>%
     set_mode("regression") %>%
-    set_engine("LiblineaR")
+    set_engine("xgboost")
 
   expect_no_error(
     lm_fit <- fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
@@ -21,7 +21,7 @@ test_that("sparse matrices can be passed to `fit_xy()", {
 })
 
 test_that("to_sparse_data_frame() is used correctly", {
-  skip_if_not_installed("LiblineaR")
+  skip_if_not_installed("xgboost")
   
   local_mocked_bindings(
     to_sparse_data_frame = function(x, object) {
@@ -50,9 +50,9 @@ test_that("to_sparse_data_frame() is used correctly", {
     fit_xy(spec, x = hotel_data[, -1], y = hotel_data[, 1])
   )
   
-  spec <- svm_linear() %>%
+  spec <- boost_tree() %>%
     set_mode("regression") %>%
-    set_engine("LiblineaR")
+    set_engine("xgboost")
 
   expect_snapshot(
     error = TRUE,
@@ -61,7 +61,7 @@ test_that("to_sparse_data_frame() is used correctly", {
 })
 
 test_that("maybe_sparse_matrix() is used correctly", {
-  skip_if_not_installed("LiblineaR")
+  skip_if_not_installed("xgboost")
   
   local_mocked_bindings(
     maybe_sparse_matrix = function(x) {
@@ -75,9 +75,9 @@ test_that("maybe_sparse_matrix() is used correctly", {
 
   hotel_data <- sparse_hotel_rates()
 
-  spec <- svm_linear() %>%
+  spec <- boost_tree() %>%
     set_mode("regression") %>%
-    set_engine("LiblineaR")
+    set_engine("xgboost")
 
   expect_snapshot(
     error = TRUE,

From a60a928936fa42b6407c0057778a4edc05b5dae0 Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 28 Aug 2024 09:14:00 -0700
Subject: [PATCH 15/16] remove leftover skip_if_not_installed

---
 tests/testthat/test-sparsevctrs.R | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index 84b0d0e39..04f673c1c 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -24,8 +24,6 @@ test_that("sparse matrices can be passed to `fit_xy()", {
 test_that("to_sparse_data_frame() is used correctly", {
   skip_if_not_installed("xgboost")
   
-  skip_if_not_installed("LiblineaR")
-
   local_mocked_bindings(
     to_sparse_data_frame = function(x, object) {
       if (methods::is(x, "sparseMatrix")) {
@@ -68,8 +66,6 @@ test_that("to_sparse_data_frame() is used correctly", {
 test_that("maybe_sparse_matrix() is used correctly", {
   skip_if_not_installed("xgboost")
   
-  skip_if_not_installed("LiblineaR")
-
   local_mocked_bindings(
     maybe_sparse_matrix = function(x) {
       if (any(vapply(x, sparsevctrs::is_sparse_vector, logical(1)))) {

From 1971f05b7c086cf9c117f15094483fd48172791d Mon Sep 17 00:00:00 2001
From: Emil Hvitfeldt <emilhhvitfeldt@gmail.com>
Date: Wed, 28 Aug 2024 10:03:10 -0700
Subject: [PATCH 16/16] fix merge issue

---
 tests/testthat/test-sparsevctrs.R | 2 --
 1 file changed, 2 deletions(-)

diff --git a/tests/testthat/test-sparsevctrs.R b/tests/testthat/test-sparsevctrs.R
index 04f673c1c..2f9027306 100644
--- a/tests/testthat/test-sparsevctrs.R
+++ b/tests/testthat/test-sparsevctrs.R
@@ -52,8 +52,6 @@ test_that("to_sparse_data_frame() is used correctly", {
   )
   
   spec <- boost_tree() %>%
-
-  spec <- svm_linear() %>%
     set_mode("regression") %>%
     set_engine("xgboost")