MAINT make sure that hstack outputs a CSR matrix (scikit-learn#26555)

glemaitre · web-flow · commit d85e22224c0e · 2023-06-09T17:35:24.000+02:00
diff --git a/sklearn/preprocessing/_polynomial.py b/sklearn/preprocessing/_polynomial.py
@@ -1145,7 +1145,7 @@ def transform(self, X):
                     " of scipy `>=1.9.2` or alter the `SplineTransformer`"
                     " transformer to produce fewer than 2^31 output features"
                 )
-            XBS = sparse.hstack(output_list)
+            XBS = sparse.hstack(output_list, format="csr")
         elif self.sparse_output:
             # TODO: Remove ones scipy 1.10 is the minimum version. See comments above.
             XBS = sparse.csr_matrix(XBS)

Original file line number	Diff line number	Diff line change
`@@ -1145,7 +1145,7 @@ def transform(self, X):`
`1145`	`1145`	" of scipy `>=1.9.2` or alter the `SplineTransformer`"
`1146`	`1146`	`" transformer to produce fewer than 2^31 output features"`
`1147`	`1147`	`)`
`1148`		`- XBS = sparse.hstack(output_list)`
	`1148`	`+ XBS = sparse.hstack(output_list, format="csr")`
`1149`	`1149`	`elif self.sparse_output:`
`1150`	`1150`	`# TODO: Remove ones scipy 1.10 is the minimum version. See comments above.`
`1151`	`1151`	`XBS = sparse.csr_matrix(XBS)`