Skip to content

Commit 50b84b5

Browse files
headlessNodekgryte
andauthored
feat: add ndarray/base/find
PR-URL: #7426 Ref: #2656 Co-authored-by: Athan Reines <[email protected]> Reviewed-by: Athan Reines <[email protected]>
1 parent bbaf951 commit 50b84b5

Some content is hidden

Large Commits have some content hidden by default. Use the searchbox below for content that may be hidden.

68 files changed

+28402
-0
lines changed
Lines changed: 246 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,246 @@
1+
<!--
2+
3+
@license Apache-2.0
4+
5+
Copyright (c) 2025 The Stdlib Authors.
6+
7+
Licensed under the Apache License, Version 2.0 (the "License");
8+
you may not use this file except in compliance with the License.
9+
You may obtain a copy of the License at
10+
11+
http://www.apache.org/licenses/LICENSE-2.0
12+
13+
Unless required by applicable law or agreed to in writing, software
14+
distributed under the License is distributed on an "AS IS" BASIS,
15+
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16+
See the License for the specific language governing permissions and
17+
limitations under the License.
18+
19+
-->
20+
21+
# find
22+
23+
> Return the first element in an ndarray which passes a test implemented by a predicate function.
24+
25+
<section class="intro">
26+
27+
</section>
28+
29+
<!-- /.intro -->
30+
31+
<section class="usage">
32+
33+
## Usage
34+
35+
<!-- eslint-disable no-redeclare -->
36+
37+
```javascript
38+
var find = require( '@stdlib/ndarray/base/find' );
39+
```
40+
41+
<!-- eslint-enable no-redeclare -->
42+
43+
#### find( arrays, predicate\[, thisArg] )
44+
45+
Returns the first element in an ndarray which passes a test implemented by a predicate function.
46+
47+
<!-- eslint-disable max-len -->
48+
49+
```javascript
50+
var Float64Array = require( '@stdlib/array/float64' );
51+
52+
function isEven( value ) {
53+
return value % 2.0 === 0.0;
54+
}
55+
56+
// Create a data buffer:
57+
var xbuf = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
58+
59+
// Define the shape of the input array:
60+
var shape = [ 3, 1, 2 ];
61+
62+
// Define the array strides:
63+
var sx = [ 4, 4, 1 ];
64+
65+
// Define the index offset:
66+
var ox = 0;
67+
68+
// Create the input ndarray-like object:
69+
var x = {
70+
'dtype': 'float64',
71+
'data': xbuf,
72+
'shape': shape,
73+
'strides': sx,
74+
'offset': ox,
75+
'order': 'row-major'
76+
};
77+
78+
// Create an ndarray-like object containing a sentinel value:
79+
var sentinelValue = {
80+
'dtype': 'float64',
81+
'data': new Float64Array( [ NaN ] ),
82+
'shape': [],
83+
'strides': [ 0 ],
84+
'offset': 0,
85+
'order': 'row-major'
86+
};
87+
88+
// Perform reduction:
89+
var out = find( [ x, sentinelValue ], isEven );
90+
// returns 2.0
91+
```
92+
93+
The function accepts the following arguments:
94+
95+
- **arrays**: array-like object containing an input ndarray and a zero-dimensional ndarray containing a sentinel value. The sentinel value is returned when no element in an input ndarray passes a test implemented by the predicate function.
96+
- **predicate**: predicate function.
97+
- **thisArg**: predicate function execution context (_optional_).
98+
99+
Each provided ndarray should be an object with the following properties:
100+
101+
- **dtype**: data type.
102+
- **data**: data buffer.
103+
- **shape**: dimensions.
104+
- **strides**: stride lengths.
105+
- **offset**: index offset.
106+
- **order**: specifies whether an ndarray is row-major (C-style) or column major (Fortran-style).
107+
108+
The predicate function is provided the following arguments:
109+
110+
- **value**: current array element.
111+
- **indices**: current array element indices.
112+
- **arr**: the input ndarray.
113+
114+
To set the predicate function execution context, provide a `thisArg`.
115+
116+
<!-- eslint-disable no-invalid-this, max-len -->
117+
118+
```javascript
119+
var Float64Array = require( '@stdlib/array/float64' );
120+
121+
function isEven( value ) {
122+
this.count += 1;
123+
return value % 2.0 === 0.0;
124+
}
125+
126+
// Create a data buffer:
127+
var xbuf = new Float64Array( [ 1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0 ] );
128+
129+
// Define the shape of the input array:
130+
var shape = [ 3, 1, 2 ];
131+
132+
// Define the array strides:
133+
var sx = [ 4, 4, 1 ];
134+
135+
// Define the index offset:
136+
var ox = 0;
137+
138+
// Create the input ndarray-like object:
139+
var x = {
140+
'dtype': 'float64',
141+
'data': xbuf,
142+
'shape': shape,
143+
'strides': sx,
144+
'offset': ox,
145+
'order': 'row-major'
146+
};
147+
148+
// Create an ndarray-like object containing a sentinel value:
149+
var sentinelValue = {
150+
'dtype': 'float64',
151+
'data': new Float64Array( [ NaN ] ),
152+
'shape': [],
153+
'strides': [ 0 ],
154+
'offset': 0,
155+
'order': 'row-major'
156+
};
157+
158+
var ctx = {
159+
'count': 0
160+
};
161+
162+
// Perform reduction:
163+
var out = find( [ x, sentinelValue ], isEven, ctx );
164+
// returns 2.0
165+
166+
var count = ctx.count;
167+
// returns 2
168+
```
169+
170+
</section>
171+
172+
<!-- /.usage -->
173+
174+
<section class="notes">
175+
176+
## Notes
177+
178+
- For very high-dimensional ndarrays which are non-contiguous, one should consider copying the underlying data to contiguous memory before performing the operation in order to achieve better performance.
179+
180+
</section>
181+
182+
<!-- /.notes -->
183+
184+
<section class="examples">
185+
186+
## Examples
187+
188+
<!-- eslint no-undef: "error" -->
189+
190+
```javascript
191+
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
192+
var Float64Array = require( '@stdlib/array/float64' );
193+
var ndarray2array = require( '@stdlib/ndarray/base/to-array' );
194+
var find = require( '@stdlib/ndarray/base/find' );
195+
196+
function isEven( value ) {
197+
return value % 2.0 === 0.0;
198+
}
199+
200+
var x = {
201+
'dtype': 'float64',
202+
'data': discreteUniform( 10, 0.0, 10.0, {
203+
'dtype': 'float64'
204+
}),
205+
'shape': [ 5, 2 ],
206+
'strides': [ 2, 1 ],
207+
'offset': 0,
208+
'order': 'row-major'
209+
};
210+
console.log( ndarray2array( x.data, x.shape, x.strides, x.offset, x.order ) );
211+
212+
var sv = {
213+
'dtype': 'float64',
214+
'data': new Float64Array( [ NaN ] ),
215+
'shape': [],
216+
'strides': [ 0 ],
217+
'offset': 0,
218+
'order': x.order
219+
};
220+
console.log( 'Sentinel Value: %d', sv.data[ 0 ] );
221+
222+
var out = find( [ x, sv ], isEven );
223+
console.log( out );
224+
```
225+
226+
</section>
227+
228+
<!-- /.examples -->
229+
230+
<!-- Section for related `stdlib` packages. Do not manually edit this section, as it is automatically populated. -->
231+
232+
<section class="related">
233+
234+
</section>
235+
236+
<!-- /.related -->
237+
238+
<section class="links">
239+
240+
<!-- <related-links> -->
241+
242+
<!-- </related-links> -->
243+
244+
</section>
245+
246+
<!-- /.links -->
Lines changed: 147 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,147 @@
1+
/**
2+
* @license Apache-2.0
3+
*
4+
* Copyright (c) 2025 The Stdlib Authors.
5+
*
6+
* Licensed under the Apache License, Version 2.0 (the "License");
7+
* you may not use this file except in compliance with the License.
8+
* You may obtain a copy of the License at
9+
*
10+
* http://www.apache.org/licenses/LICENSE-2.0
11+
*
12+
* Unless required by applicable law or agreed to in writing, software
13+
* distributed under the License is distributed on an "AS IS" BASIS,
14+
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15+
* See the License for the specific language governing permissions and
16+
* limitations under the License.
17+
*/
18+
19+
'use strict';
20+
21+
/* eslint-disable stdlib/no-redeclare */
22+
23+
// MODULES //
24+
25+
var bench = require( '@stdlib/bench' );
26+
var isInteger = require( '@stdlib/math/base/assert/is-integer' );
27+
var pow = require( '@stdlib/math/base/special/pow' );
28+
var floor = require( '@stdlib/math/base/special/floor' );
29+
var discreteUniform = require( '@stdlib/random/array/discrete-uniform' );
30+
var shape2strides = require( '@stdlib/ndarray/base/shape2strides' );
31+
var pkg = require( './../package.json' ).name;
32+
var find = require( './../lib/10d.js' );
33+
34+
35+
// VARIABLES //
36+
37+
var types = [ 'float64' ];
38+
var order = 'column-major';
39+
40+
41+
// FUNCTIONS //
42+
43+
/**
44+
* Callback function.
45+
*
46+
* @param {*} value - ndarray element
47+
* @returns {boolean} result
48+
*/
49+
function clbk( value ) {
50+
return value < 0.0;
51+
}
52+
53+
/**
54+
* Creates a benchmark function.
55+
*
56+
* @private
57+
* @param {PositiveInteger} len - ndarray length
58+
* @param {NonNegativeIntegerArray} shape - ndarray shape
59+
* @param {string} xtype - ndarray data type
60+
* @returns {Function} benchmark function
61+
*/
62+
function createBenchmark( len, shape, xtype ) {
63+
var x;
64+
65+
x = discreteUniform( len, 1, 100, {
66+
'dtype': xtype
67+
});
68+
x = {
69+
'dtype': xtype,
70+
'data': x,
71+
'shape': shape,
72+
'strides': shape2strides( shape, order ),
73+
'offset': 0,
74+
'order': order
75+
};
76+
return benchmark;
77+
78+
/**
79+
* Benchmark function.
80+
*
81+
* @private
82+
* @param {Benchmark} b - benchmark instance
83+
*/
84+
function benchmark( b ) {
85+
var out;
86+
var i;
87+
88+
b.tic();
89+
for ( i = 0; i < b.iterations; i++ ) {
90+
out = find( x, NaN, clbk );
91+
if ( isInteger( out ) ) {
92+
b.fail( 'should not return an integer' );
93+
}
94+
}
95+
b.toc();
96+
if ( isInteger( out ) ) {
97+
b.fail( 'should not return an integer' );
98+
}
99+
b.pass( 'benchmark finished' );
100+
b.end();
101+
}
102+
}
103+
104+
105+
// MAIN //
106+
107+
/**
108+
* Main execution sequence.
109+
*
110+
* @private
111+
*/
112+
function main() {
113+
var len;
114+
var min;
115+
var max;
116+
var sh;
117+
var t1;
118+
var f;
119+
var i;
120+
var j;
121+
122+
min = 1; // 10^min
123+
max = 5; // 10^max
124+
125+
for ( j = 0; j < types.length; j++ ) {
126+
t1 = types[ j ];
127+
for ( i = min; i <= max; i++ ) {
128+
len = pow( 10, i );
129+
130+
sh = [ len/2, 2, 1, 1, 1, 1, 1, 1, 1, 1 ];
131+
f = createBenchmark( len, sh, t1 );
132+
bench( pkg+':ndims='+sh.length+',len='+len+',shape=['+sh.join(',')+'],xorder='+order+',xtype='+t1, f );
133+
134+
sh = [ 1, 1, 1, 1, 1, 1, 1, 1, 2, len/2 ];
135+
f = createBenchmark( len, sh, t1 );
136+
bench( pkg+':ndims='+sh.length+',len='+len+',shape=['+sh.join(',')+'],xorder='+order+',xtype='+t1, f );
137+
138+
len = floor( pow( len, 1.0/10.0 ) );
139+
sh = [ len, len, len, len, len, len, len, len, len, len ];
140+
len *= pow( len, 9 );
141+
f = createBenchmark( len, sh, t1 );
142+
bench( pkg+':ndims='+sh.length+',len='+len+',shape=['+sh.join(',')+'],xorder='+order+',xtype='+t1, f );
143+
}
144+
}
145+
}
146+
147+
main();

0 commit comments

Comments
 (0)