diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/README.md b/lib/node_modules/@stdlib/stats/incr/nanmda/README.md
new file mode 100644
index 000000000000..7029ed5f4660
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/README.md
@@ -0,0 +1,175 @@
+
+
+# incrnanmda
+
+> Compute the [mean directional accuracy][mean-directional-accuracy] (MDA) incrementally, ignoring `NaN` value.
+
+
+
+The [mean directional accuracy][mean-directional-accuracy] is defined as
+
+
+
+```math
+\mathop{\mathrm{MDA}} = \begin{cases} 1 & \textrm{if}\ N = 1 \\\frac{1}{N} \sum_{i=1}^{N} \delta_{\mathop{\mathrm{sgn}}(\Delta f_{i,i-1}),\ \mathop{\mathrm{sgn}}(\Delta a_{i,i-1})} & \textrm{if}\ N > 1 \end{cases}
+```
+
+
+
+
+
+where `f_i` is the forecast value, `a_i` is the actual value, `sgn(x)` is the [signum][@stdlib/math/base/special/signum] function, and `δ` is the [Kronecker delta][@stdlib/math/base/special/kronecker-delta].
+
+
+
+
+
+
+
+## Usage
+
+```javascript
+var incrnanmda = require( '@stdlib/stats/incr/nanmda' );
+```
+
+#### incrnanmda()
+
+Returns an accumulator `function` which incrementally computes the [mean directional accuracy][mean-directional-accuracy], ignoring `NaN` value.
+
+```javascript
+var accumulator = incrnanmda();
+```
+
+#### accumulator( \[f, a] )
+
+If provided input values `f` and `a`, the accumulator function returns an updated [mean directional accuracy][mean-directional-accuracy]. If not provided input values `f` and `a`, the accumulator function returns the current [mean directional accuracy][mean-directional-accuracy].
+
+```javascript
+var accumulator = incrnanmda();
+
+var m = accumulator( 2.0, 3.0 );
+// returns 1.0
+
+m = accumulator( -1.0, 4.0 );
+// returns 0.5
+
+m = accumulator( NaN, 4.0 );
+// returns 0.5
+
+m = accumulator( -3.0, -2.0 );
+// returns ~0.67
+
+m = accumulator();
+// returns ~0.67
+```
+
+
+
+
+
+
+
+## Notes
+
+- Input values are type checked. If provided a NaN or a non-numeric value, the update is skipped and the accumulator returns the previously computed mean directional accuracy. If non-numeric inputs are possible, you are advised to type check and handle accordingly before passing the value to the accumulator function.
+
+
+
+
+
+
+
+## Examples
+
+
+
+```javascript
+var randu = require( '@stdlib/random/base/randu' );
+var incrnanmda = require( '@stdlib/stats/incr/nanmda' );
+
+var accumulator;
+var v1;
+var v2;
+var i;
+
+// Initialize an accumulator:
+accumulator = incrnanmda();
+
+// For each simulated datum, update the mean directional accuracy...
+for ( i = 0; i < 100; i++ ) {
+ if ( randu() < 0.2 ) {
+ v1 = NaN;
+ } else {
+ v1 = ( randu()*100.0 ) - 50.0;
+ }
+ if ( randu() < 0.2 ) {
+ v2 = NaN;
+ } else {
+ v2 = ( randu()*100.0 ) - 50.0;
+ }
+ accumulator( v1, v2 );
+}
+console.log( accumulator() );
+```
+
+
+
+
+
+
+
+
+
+* * *
+
+## See Also
+
+- [`@stdlib/stats/incr/mape`][@stdlib/stats/incr/mape]: compute the mean absolute percentage error (MAPE) incrementally.
+- [`@stdlib/stats/incr/mmda`][@stdlib/stats/incr/mmda]: compute a moving mean directional accuracy (MDA) incrementally.
+
+
+
+
+
+
+
+
+
+[mean-directional-accuracy]: https://en.wikipedia.org/wiki/Mean_Directional_Accuracy_%28MDA%29
+
+[@stdlib/math/base/special/signum]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/signum
+
+[@stdlib/math/base/special/kronecker-delta]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/math/base/special/kronecker-delta
+
+
+
+[@stdlib/stats/incr/mape]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/incr/mape
+
+[@stdlib/stats/incr/mmda]: https://github.com/stdlib-js/stdlib/tree/develop/lib/node_modules/%40stdlib/stats/incr/mmda
+
+
+
+
+
+
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/benchmark/benchmark.js b/lib/node_modules/@stdlib/stats/incr/nanmda/benchmark/benchmark.js
new file mode 100644
index 000000000000..37dc07703143
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/benchmark/benchmark.js
@@ -0,0 +1,69 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var bench = require( '@stdlib/bench' );
+var randu = require( '@stdlib/random/base/randu' );
+var pkg = require( './../package.json' ).name;
+var incrnanmda = require( './../lib' );
+
+
+// MAIN //
+
+bench( pkg, function benchmark( b ) {
+ var f;
+ var i;
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ f = incrnanmda();
+ if ( typeof f !== 'function' ) {
+ b.fail( 'should return a function' );
+ }
+ }
+ b.toc();
+ if ( typeof f !== 'function' ) {
+ b.fail( 'should return a function' );
+ }
+ b.pass( 'benchmark finished' );
+ b.end();
+});
+
+bench( pkg+'::accumulator', function benchmark( b ) {
+ var acc;
+ var v;
+ var i;
+
+ acc = incrnanmda();
+
+ b.tic();
+ for ( i = 0; i < b.iterations; i++ ) {
+ v = acc( randu()-0.5, randu()-0.5 );
+ if ( v !== v ) {
+ b.fail( 'should not return NaN' );
+ }
+ }
+ b.toc();
+ if ( v !== v ) {
+ b.fail( 'should not return NaN' );
+ }
+ b.pass( 'benchmark finished' );
+ b.end();
+});
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/docs/img/equation_mean_directional_accuracy.svg b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/img/equation_mean_directional_accuracy.svg
new file mode 100644
index 000000000000..c289bdf791d2
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/img/equation_mean_directional_accuracy.svg
@@ -0,0 +1,115 @@
+
\ No newline at end of file
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/docs/repl.txt b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/repl.txt
new file mode 100644
index 000000000000..d9576e8203d4
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/repl.txt
@@ -0,0 +1,34 @@
+
+{{alias}}()
+ Returns an accumulator function which incrementally computes the mean
+ directional accuracy (MDA), ignoring `NaN` value.
+
+ If provided input values, the accumulator function returns an updated mean
+ directional accuracy. If not provided input values, the accumulator function
+ returns the current mean directional accuracy.
+
+ If provided `NaN` or a value which, when used in computations, results in
+ `NaN`, the accumulated value is `NaN` for all future invocations.
+
+ Returns
+ -------
+ acc: Function
+ Accumulator function.
+
+ Examples
+ --------
+ > var accumulator = {{alias}}();
+ > var m = accumulator()
+ null
+ > m = accumulator( 2.0, 3.0 )
+ 1.0
+ > m = accumulator( -5.0, 4.0 )
+ 0.5
+ > m = accumulator( NaN, 4.0 )
+ 0.5
+ > m = accumulator()
+ 0.5
+
+ See Also
+ --------
+
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/index.d.ts b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/index.d.ts
new file mode 100644
index 000000000000..1560e2cc9ed3
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/index.d.ts
@@ -0,0 +1,64 @@
+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+// TypeScript Version: 4.1
+
+///
+
+/**
+* If provided a value, the accumulator function returns an updated mean directional accuracy. If not provided a value, the accumulator function returns the current mean directional accuracy.
+*
+* ## Notes
+*
+* - If provided `NaN` or a value which, when used in computations, results in `NaN`, the accumulated value is `NaN` for all future invocations.
+*
+* @param f - forecast value
+* @param a - actual value
+* @returns mean directional accuracy or null
+*/
+type accumulator = ( f?: number, a?: number ) => number | null;
+
+/**
+* Returns an accumulator function which incrementally computes the mean directional accuracy, ignoring `NaN` value.
+*
+* @returns accumulator function
+*
+* @example
+* var accumulator = incrnanmda();
+*
+* var m = accumulator();
+* // returns null
+*
+* m = accumulator( 2.0, 3.0 );
+* // returns 1.0
+*
+* m = accumulator( -5.0, 4.0 );
+* // returns 0.5
+*
+* m = accumulator( NaN, 4.0 );
+* // returns 0.5
+*
+* m = accumulator();
+* // returns 0.5
+*/
+declare function incrnanmda(): accumulator;
+
+
+// EXPORTS //
+
+export = incrnanmda;
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/test.ts b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/test.ts
new file mode 100644
index 000000000000..12aa31807feb
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/docs/types/test.ts
@@ -0,0 +1,69 @@
+/*
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+import innancrmda = require( './index' );
+
+
+// TESTS //
+
+// The function returns an accumulator function...
+{
+ innancrmda(); // $ExpectType accumulator
+}
+
+// The compiler throws an error if the function is provided arguments...
+{
+ innancrmda( '5' ); // $ExpectError
+ innancrmda( 5 ); // $ExpectError
+ innancrmda( true ); // $ExpectError
+ innancrmda( false ); // $ExpectError
+ innancrmda( null ); // $ExpectError
+ innancrmda( undefined ); // $ExpectError
+ innancrmda( [] ); // $ExpectError
+ innancrmda( {} ); // $ExpectError
+ innancrmda( ( x: number ): number => x ); // $ExpectError
+}
+
+// The function returns an accumulator function which returns an accumulated result...
+{
+ const acc = innancrmda();
+
+ acc(); // $ExpectType number | null
+ acc( 3.14, 2.0 ); // $ExpectType number | null
+}
+
+// The compiler throws an error if the returned accumulator function is provided invalid arguments...
+{
+ const acc = innancrmda();
+
+ acc( '5', 2.0 ); // $ExpectError
+ acc( true, 2.0 ); // $ExpectError
+ acc( false, 2.0 ); // $ExpectError
+ acc( null, 2.0 ); // $ExpectError
+ acc( [], 2.0 ); // $ExpectError
+ acc( {}, 2.0 ); // $ExpectError
+ acc( ( x: number ): number => x, 2.0 ); // $ExpectError
+
+ acc( 3.14, '5' ); // $ExpectError
+ acc( 3.14, true ); // $ExpectError
+ acc( 3.14, false ); // $ExpectError
+ acc( 3.14, null ); // $ExpectError
+ acc( 3.14, [] ); // $ExpectError
+ acc( 3.14, {} ); // $ExpectError
+ acc( 3.14, ( x: number ): number => x ); // $ExpectError
+}
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/examples/index.js b/lib/node_modules/@stdlib/stats/incr/nanmda/examples/index.js
new file mode 100644
index 000000000000..176d4b68da0c
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/examples/index.js
@@ -0,0 +1,49 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+var randu = require( '@stdlib/random/base/randu' );
+var incrnanmda = require( './../lib' );
+
+var accumulator;
+var v2;
+var v1;
+var m;
+var i;
+
+// Initialize an accumulator:
+accumulator = incrnanmda();
+
+// For each simulated datum, update the mean directional accuracy...
+console.log( '\nValue\tValue\tMDA\n' );
+for ( i = 0; i < 100; i++ ) {
+ if ( randu() < 0.1 ) {
+ v1 = NaN;
+ } else {
+ v1 = ( randu()*100.0 ) - 50.0;
+ }
+ if ( randu() < 0.1 ) {
+ v2 = NaN;
+ } else {
+ v2 = ( randu()*100.0 ) - 50.0;
+ }
+ m = accumulator( v1, v2 );
+ console.log( '%d\t%d\t%d', v1.toFixed( 3 ), v2.toFixed( 3 ), m.toFixed( 3 ) );
+}
+console.log( '\nFinal MDA: %d\n', accumulator() );
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/lib/index.js b/lib/node_modules/@stdlib/stats/incr/nanmda/lib/index.js
new file mode 100644
index 000000000000..dec2415dff35
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/lib/index.js
@@ -0,0 +1,54 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+/**
+* Compute the mean directional accuracy (MDA) incrementally, ignoring `NaN` value.
+*
+* @module @stdlib/stats/incr/nanmda
+*
+* @example
+* var incrnanmda = require( '@stdlib/stats/incr/nanmda' );
+*
+* var accumulator = incrnanmda();
+*
+* var m = accumulator();
+* // returns null
+*
+* m = accumulator( 2.0, 3.0 );
+* // returns 1.0
+*
+* m = accumulator( -5.0, 4.0 );
+* // returns 0.5
+*
+* m = accumulator( NaN, 4.0 );
+* // returns 0.5
+*
+* m = accumulator();
+* // returns 0.5
+*/
+
+// MODULES //
+
+var main = require( './main.js' );
+
+
+// EXPORTS //
+
+module.exports = main;
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/lib/main.js b/lib/node_modules/@stdlib/stats/incr/nanmda/lib/main.js
new file mode 100644
index 000000000000..ccd52031a7e0
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/lib/main.js
@@ -0,0 +1,76 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var incrmda = require( '@stdlib/stats/incr/mda' );
+var isnan = require( '@stdlib/math/base/assert/is-nan' );
+var isNumber = require( '@stdlib/assert/is-number' ).isPrimitive;
+
+
+// MAIN //
+
+/**
+* Returns an accumulator function which incrementally computes the mean directional accuracy, ignoring `NaN` value.
+*
+* @returns {Function} accumulator function
+*
+* @example
+* var accumulator = incrnanmda();
+*
+* var m = accumulator();
+* // returns null
+*
+* m = accumulator( 2.0, 3.0 );
+* // returns 1.0
+*
+* m = accumulator( -5.0, 4.0 );
+* // returns 0.5
+*
+* m = accumulator( NaN, 4.0 );
+* // returns 0.5
+*
+* m = accumulator();
+* // returns 0.5
+*/
+function incrnanmda() {
+ var mda = incrmda();
+ return accumulator;
+
+ /**
+ * If provided a value, the accumulator function returns an updated mean directional accuracy. If not provided a value, the accumulator function returns the current mean directional accuracy.
+ *
+ * @private
+ * @param {number} [f] - forecast value
+ * @param {number} [a] - actual value
+ * @returns {(number|null)} mean directional accuracy or null
+ */
+ function accumulator( f, a ) {
+ if ( arguments.length === 0 || isnan( f ) || isnan( a ) || !isNumber( f ) || !isNumber( a )) {
+ return mda();
+ }
+ return mda( f, a );
+ }
+}
+
+
+// EXPORTS //
+
+module.exports = incrnanmda;
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/package.json b/lib/node_modules/@stdlib/stats/incr/nanmda/package.json
new file mode 100644
index 000000000000..1c934378fe82
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/package.json
@@ -0,0 +1,76 @@
+{
+ "name": "@stdlib/stats/incr/nanmda",
+ "version": "0.0.0",
+ "description": "Compute the mean directional accuracy (MDA) incrementally.",
+ "license": "Apache-2.0",
+ "author": {
+ "name": "The Stdlib Authors",
+ "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+ },
+ "contributors": [
+ {
+ "name": "The Stdlib Authors",
+ "url": "https://github.com/stdlib-js/stdlib/graphs/contributors"
+ }
+ ],
+ "main": "./lib",
+ "directories": {
+ "benchmark": "./benchmark",
+ "doc": "./docs",
+ "example": "./examples",
+ "lib": "./lib",
+ "test": "./test"
+ },
+ "types": "./docs/types",
+ "scripts": {},
+ "homepage": "https://github.com/stdlib-js/stdlib",
+ "repository": {
+ "type": "git",
+ "url": "git://github.com/stdlib-js/stdlib.git"
+ },
+ "bugs": {
+ "url": "https://github.com/stdlib-js/stdlib/issues"
+ },
+ "dependencies": {},
+ "devDependencies": {},
+ "engines": {
+ "node": ">=0.10.0",
+ "npm": ">2.7.0"
+ },
+ "os": [
+ "aix",
+ "darwin",
+ "freebsd",
+ "linux",
+ "macos",
+ "openbsd",
+ "sunos",
+ "win32",
+ "windows"
+ ],
+ "keywords": [
+ "stdlib",
+ "stdmath",
+ "statistics",
+ "stats",
+ "mathematics",
+ "math",
+ "average",
+ "avg",
+ "mean",
+ "direction",
+ "directional",
+ "accuracy",
+ "trend",
+ "incremental",
+ "accumulator",
+ "time series",
+ "timeseries",
+ "demand",
+ "forecasting",
+ "forecast",
+ "economics",
+ "econ",
+ "finance"
+ ]
+}
diff --git a/lib/node_modules/@stdlib/stats/incr/nanmda/test/test.js b/lib/node_modules/@stdlib/stats/incr/nanmda/test/test.js
new file mode 100644
index 000000000000..8cb75517c35b
--- /dev/null
+++ b/lib/node_modules/@stdlib/stats/incr/nanmda/test/test.js
@@ -0,0 +1,110 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+* http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+'use strict';
+
+// MODULES //
+
+var tape = require( 'tape' );
+var abs = require( '@stdlib/math/base/special/abs' );
+var EPS = require( '@stdlib/constants/float64/eps' );
+var incrnanmda = require( './../lib' );
+
+
+// TESTS //
+
+tape( 'main export is a function', function test( t ) {
+ t.ok( true, __filename );
+ t.strictEqual( typeof incrnanmda, 'function', 'main export is a function' );
+ t.end();
+});
+
+tape( 'the function returns an accumulator function', function test( t ) {
+ t.equal( typeof incrnanmda(), 'function', 'returns a function' );
+ t.end();
+});
+
+tape( 'the initial accumulated value is `null`', function test( t ) {
+ var acc = incrnanmda();
+ t.equal( acc(), null, 'returns expected value' );
+ t.end();
+});
+
+tape( 'the accumulator function incrementally computes the mean directional accuracy', function test( t ) {
+ var expected;
+ var actual;
+ var delta;
+ var data;
+ var acc;
+ var tol;
+ var N;
+ var i;
+
+ data = [
+ [ 2.0, -3.0 ], // +,+
+ [ 3.0, 1.0 ], // +,+
+ [ NaN, 1.0 ], // +,+
+ [ 2.0, 5.0 ], // -,+
+ [ 4.0, -4.0 ], // +,-
+ [ -3.0, -1.0 ], // -,+
+ [ 4.0, 5.0 ] // +,-
+ ];
+ N = data.length;
+
+ expected = [
+ 1.0,
+ 2.0/2.0,
+ 2.0/2.0,
+ 2.0/3.0,
+ 2.0/4.0,
+ 2.0/5.0,
+ 3.0/6.0
+ ];
+
+ acc = incrnanmda();
+ for ( i = 0; i < N; i++ ) {
+ actual = acc( data[ i ][ 0 ], data[ i ][ 1 ] );
+ if ( actual === expected[ i ] ) {
+ t.equal( actual, expected[ i ], 'returns expected value' );
+ } else {
+ delta = abs( expected[ i ] - actual );
+ tol = 1.0 * EPS * abs( expected[ i ] );
+ t.equal( delta <= tol, true, 'within tolerance. Actual: '+actual+'. Expected: '+expected[ i ]+'. Delta: '+delta+'. Tol: '+tol+'.' );
+ }
+ }
+ t.end();
+});
+
+tape( 'if not provided an input value, the accumulator function returns the current mean directional accuracy', function test( t ) {
+ var data;
+ var acc;
+ var i;
+
+ data = [
+ [ 2.0, -3.0 ], // +,+
+ [ NaN, -3.0 ], // +,+
+ [ -3.0, 5.0 ], // -,+
+ [ -1.0, 14.0 ] // +,+
+ ];
+ acc = incrnanmda();
+ for ( i = 0; i < data.length; i++ ) {
+ acc( data[ i ][ 0 ], data[ i ][ 1 ] );
+ }
+ t.equal( acc(), 2.0/3.0, 'returns expected value' );
+ t.end();
+});