feat: add C implementation for `math/base/special/heaviside` by officiallyanee · Pull Request #9844 · stdlib-js/stdlib

officiallyanee · 2026-01-21T01:10:48Z

type: pre_commit_static_analysis_report
description: Results of running static analysis checks when committing changes. report:

task: lint_filenames status: passed
task: lint_editorconfig status: passed
task: lint_markdown status: passed
task: lint_package_json status: passed
task: lint_repl_help status: na
task: lint_javascript_src status: passed
task: lint_javascript_cli status: na
task: lint_javascript_examples status: na
task: lint_javascript_tests status: passed
task: lint_javascript_benchmarks status: passed
task: lint_python status: na
task: lint_r status: na
task: lint_c_src status: passed
task: lint_c_examples status: passed
task: lint_c_benchmarks status: passed
task: lint_c_tests_fixtures status: na
task: lint_shell status: na
task: lint_typescript_declarations status: passed
task: lint_typescript_tests status: na
task: lint_license_headers status: passed ---

Resolves none.

Description

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This pull request:

Adds the c implementation for math/base/special/heaviside

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

progresses [RFC]: Add C implementations to base special math functions (tracking issue) #649 .

Questions

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No.

Other

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No.

Checklist

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Read, understood, and followed the contributing guidelines.

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--- type: pre_commit_static_analysis_report description: Results of running static analysis checks when committing changes. report: - task: lint_filenames status: passed - task: lint_editorconfig status: passed - task: lint_markdown status: passed - task: lint_package_json status: passed - task: lint_repl_help status: na - task: lint_javascript_src status: passed - task: lint_javascript_cli status: na - task: lint_javascript_examples status: na - task: lint_javascript_tests status: passed - task: lint_javascript_benchmarks status: passed - task: lint_python status: na - task: lint_r status: na - task: lint_c_src status: passed - task: lint_c_examples status: passed - task: lint_c_benchmarks status: passed - task: lint_c_tests_fixtures status: na - task: lint_shell status: na - task: lint_typescript_declarations status: passed - task: lint_typescript_tests status: na - task: lint_license_headers status: passed ---

stdlib-bot · 2026-01-21T01:13:34Z

Coverage Report

Package	Statements	Branches	Functions	Lines
math/base/special/heaviside	$\color{green}300/300$ $\color{green}+0.00%$	$\color{green}22/22$ $\color{green}+0.00%$	$\color{green}4/4$ $\color{green}+0.00%$	$\color{green}300/300$ $\color{green}+0.00%$

The above coverage report was generated for the changes in this PR.

Planeshifter

This PR seems somewhat confused. The title doesn't match the PR body of adding a C implementation, and a lot of the additions seem to be for a float32 variant (which would be heavisidef) instead of the float64 one. Please take a closer look at your proposed changes in addition to addressing the comments I left.

Planeshifter · 2026-01-21T06:15:08Z

+
+// MAIN //
+
+bench( format( '::native', pkg, opts ), function benchmark( b ) {


The benchmark name format here isn't quite right. The format() call is passing pkg and opts but the format string '::native' has no specifiers, so pkg is ignored. Also, opts needs to be the second argument to bench(), not to format().

Planeshifter · 2026-01-21T06:15:09Z

+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		// DISCONTINUOUS
+		y = heaviside( x[ i%x.length ] );


Missing the second argument here. Since the benchmark comment says // DISCONTINUOUS, you'll want to pass 'discontinuous' as the continuity option:

Suggested change

y = heaviside( x[ i%x.length ] );

y = heaviside( x[ i%x.length ], 'discontinuous' );

Planeshifter · 2026-01-21T06:15:11Z

+	b.end();
+});
+
+bench( format( '::native:left-continuous', pkg, opts ), function benchmark( b ) {


Same benchmark name format issue here - opts needs to be the second argument to bench().

Planeshifter · 2026-01-21T06:15:12Z

+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		// LEFT_CONTINUOUS
+		y = heaviside( x[ i%x.length ], 1 );


The native.js wrapper expects a string continuity value that gets converted via str2enum. Passing an integer here will cause str2enum to return -1, which hits the default case in the C code and returns NaN for x == 0.

Suggested change

y = heaviside( x[ i%x.length ], 1 );

y = heaviside( x[ i%x.length ], 'left-continuous' );

Planeshifter · 2026-01-21T06:15:13Z

+	b.end();
+});
+
+bench( format( '::native:right-continuous', pkg, opts ), function benchmark( b ) {


Same benchmark name format issue.

Planeshifter · 2026-01-21T06:15:16Z

+	b.tic();
+	for ( i = 0; i < b.iterations; i++ ) {
+		// HALF_MAXIMUM
+		y = heaviside( x[ i%x.length ], 0 );


Same issue - needs a string instead of integer:

Suggested change

y = heaviside( x[ i%x.length ], 0 );

y = heaviside( x[ i%x.length ], 'half-maximum' );

Planeshifter · 2026-01-21T06:15:30Z

+}
+#endif
+
+#endif // !STDLIB_MATH_BASE_SPECIAL_HEAVISIDEF_H


Small typo in the header guard comment - extra 'F' snuck in:

Suggested change

#endif // !STDLIB_MATH_BASE_SPECIAL_HEAVISIDEF_H

#endif // !STDLIB_MATH_BASE_SPECIAL_HEAVISIDE_H

Planeshifter · 2026-01-21T06:15:32Z

+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.


Copyright year should be 2026 for new files:

Suggested change

* Copyright (c) 2025 The Stdlib Authors.

* Copyright (c) 2026 The Stdlib Authors.

Planeshifter · 2026-01-21T06:15:33Z

+* @return              function value
+*
+* @example
+* double y = stdlib_base_heaviside( -9.0 );


The example is missing the second parameter. The function requires both x and continuity:

Suggested change

* double y = stdlib_base_heaviside( -9.0 );

* double y = stdlib_base_heaviside( -9.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );

Planeshifter · 2026-01-21T06:15:34Z

+Evaluates the [Heaviside function][heaviside-function].
+
+```c
+float y = stdlib_base_heaviside( 0.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );


The function returns double, not float. Let's fix the variable type:

Suggested change

float y = stdlib_base_heaviside( 0.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );

double y = stdlib_base_heaviside( 0.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );

…rameter passing & typo in examples --- type: pre_commit_static_analysis_report description: Results of running static analysis checks when committing changes. report: - task: lint_filenames status: passed - task: lint_editorconfig status: passed - task: lint_markdown status: passed - task: lint_package_json status: na - task: lint_repl_help status: na - task: lint_javascript_src status: passed - task: lint_javascript_cli status: na - task: lint_javascript_examples status: na - task: lint_javascript_tests status: na - task: lint_javascript_benchmarks status: passed - task: lint_python status: na - task: lint_r status: na - task: lint_c_src status: passed - task: lint_c_examples status: na - task: lint_c_benchmarks status: na - task: lint_c_tests_fixtures status: na - task: lint_shell status: na - task: lint_typescript_declarations status: passed - task: lint_typescript_tests status: na - task: lint_license_headers status: passed ---

officiallyanee · 2026-01-21T20:03:09Z

@Planeshifter thank you for the review!

I have done the changes you mentioned , but i did not find any float32 additions other than the ones you mentioned.

kgryte · 2026-01-25T03:14:41Z

@officiallyanee Is there a reason why you chose to open this PR when we already have

?

officiallyanee · 2026-01-25T06:31:30Z

@officiallyanee Is there a reason why you chose to open this PR when we already have

feat: add C implementation for math/base/special/heaviside #6972

feat: add C implementation for math/base/special/heaviside #6823

?

I apologize, there were a lot of PRs under this issue majority of which were merged if they were not newer PRs. I didn't see code for it in the develop branch and none of the recent PRs addressed it so I went ahead with it.

stdlib-bot added Math Issue or pull request specific to math functionality. Needs Review A pull request which needs code review. labels Jan 21, 2026

Planeshifter changed the title ~~feat: add math/base/special/heaviside~~ feat: add math/base/special/heaviside Jan 21, 2026

Planeshifter requested changes Jan 21, 2026

View reviewed changes

Planeshifter added Needs Changes Pull request which needs changes before being merged. and removed Needs Review A pull request which needs code review. labels Jan 21, 2026

officiallyanee changed the title ~~feat: add math/base/special/heaviside~~ feat: add C implementation for math/base/special/heaviside Jan 21, 2026

officiallyanee closed this Jan 25, 2026


		// MAIN //

		bench( format( '::native', pkg, opts ), function benchmark( b ) {

	y = heaviside( x[ i%x.length ] );
	y = heaviside( x[ i%x.length ], 'discontinuous' );

	y = heaviside( x[ i%x.length ], 1 );
	y = heaviside( x[ i%x.length ], 'left-continuous' );

	y = heaviside( x[ i%x.length ], 0 );
	y = heaviside( x[ i%x.length ], 'half-maximum' );

	#endif // !STDLIB_MATH_BASE_SPECIAL_HEAVISIDEF_H
	#endif // !STDLIB_MATH_BASE_SPECIAL_HEAVISIDE_H

	* Copyright (c) 2025 The Stdlib Authors.
	* Copyright (c) 2026 The Stdlib Authors.

	* double y = stdlib_base_heaviside( -9.0 );
	* double y = stdlib_base_heaviside( -9.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );

	float y = stdlib_base_heaviside( 0.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );
	double y = stdlib_base_heaviside( 0.0, STDLIB_BASE_HEAVISIDE_CONTINUITY_HALF_MAXIMUM );

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officiallyanee commented Jan 21, 2026

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kgryte commented Jan 25, 2026

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