diff options
| author | sanine-a <sanine.not@pm.me> | 2023-08-01 17:03:28 -0500 |
|---|---|---|
| committer | sanine-a <sanine.not@pm.me> | 2023-08-01 17:03:28 -0500 |
| commit | 6aae1f6fb4cf289ecf5ed318b34c0e7df62bbf83 (patch) | |
| tree | 85fb52a6be571758d45f25137f08ecf04dbe91fe /src | |
| parent | 1dec9525213de7b8c23bf3393b2b76a46e27f6c7 (diff) | |
add mutation_type and mutate()
Diffstat (limited to 'src')
| -rw-r--r-- | src/genome/genome.js | 49 | ||||
| -rw-r--r-- | src/genome/genome.test.js | 20 |
2 files changed, 69 insertions, 0 deletions
diff --git a/src/genome/genome.js b/src/genome/genome.js new file mode 100644 index 0000000..16de162 --- /dev/null +++ b/src/genome/genome.js @@ -0,0 +1,49 @@ +'use strict';
+
+
+export const mutation_type = Object.freeze({
+ none: 'none',
+ source: 'source',
+ sink: 'sink',
+ weight: 'weight',
+});
+
+
+function positive(x) {
+ if (x < 0) {
+ return 0;
+ } else {
+ return x;
+ }
+}
+
+
+export function mutate(gene, type, value) {
+ const [ source, sink, weight ] = gene;
+
+ switch(type) {
+ case mutation_type.none:
+ return [...gene];
+
+ case mutation_type.source:
+ if (value <= 0.5) {
+ return [ positive(source-1), sink, weight ];
+ } else {
+ return [ source+1, sink, weight ];
+ }
+
+ case mutation_type.sink:
+ if (value <= 0.5) {
+ return [ source, positive(sink-1), weight ];
+ } else {
+ return [ source, sink+1, weight ];
+ }
+
+ case mutation_type.weight:
+ const w = (8*value) - 4;
+ return [ source, sink, w ];
+
+ default:
+ throw new Error(`unknown mutation type: '${type}'`);
+ };
+}
diff --git a/src/genome/genome.test.js b/src/genome/genome.test.js new file mode 100644 index 0000000..853d103 --- /dev/null +++ b/src/genome/genome.test.js @@ -0,0 +1,20 @@ +'use strict';
+
+import { mutation_type, mutate } from './genome';
+
+
+test('basic gene mutations', () => {
+ expect(mutate([0, 1, 2], mutation_type.none, 0)).toEqual([0, 1, 2]);
+
+ expect(mutate([0, 1, 2], mutation_type.source, 0.2)).toEqual([0, 1, 2]);
+ expect(mutate([1, 1, 2], mutation_type.source, 0.2)).toEqual([0, 1, 2]);
+ expect(mutate([0, 1, 2], mutation_type.source, 0.8)).toEqual([1, 1, 2]);
+
+ expect(mutate([0, 1, 2], mutation_type.sink, 0.2)).toEqual([0, 0, 2]);
+ expect(mutate([0, 1, 2], mutation_type.sink, 0.8)).toEqual([0, 2, 2]);
+ expect(mutate([0, 0, 2], mutation_type.sink, 0.2)).toEqual([0, 0, 2]);
+
+ expect(mutate([0, 1, 2], mutation_type.weight, 0.5)).toEqual([0, 1, 0]);
+ expect(mutate([0, 1, 2], mutation_type.weight, 0.0)).toEqual([0, 1, -4]);
+ expect(mutate([0, 1, 2], mutation_type.weight, 1.0)).toEqual([0, 1, 4]);
+});
|