diff options
Diffstat (limited to 'src/genome/genome.js')
| -rw-r--r-- | src/genome/genome.js | 218 |
1 files changed, 0 insertions, 218 deletions
diff --git a/src/genome/genome.js b/src/genome/genome.js deleted file mode 100644 index 20974fc..0000000 --- a/src/genome/genome.js +++ /dev/null @@ -1,218 +0,0 @@ -'use strict';
-
-import { random_choice } from '../util.js';
-import { network } from '../mind/topology.js';
-
-
-// check if a given genome is valid and compute its size
-export function validate_genome(genome) {
- const { n_input, n_internal, n_output } = genome;
- console.log(n_input + n_internal);
- return genome.genes.reduce(
- (acc, [source, sink, weight]) => acc && (
- (source < n_input+n_internal) &&
- (sink >= n_input)
- ),
- true
- );
-}
-
-// parse a genome into a useable neural net
-export function parse_genome(genome) {
- const { n_input, n_internal, n_output } = genome;
-
- const n = genome.genes.reduce(
- (acc, [source, sink, weight]) => acc.connect(source, sink, weight),
- network(n_input, n_internal, n_output)
- );
-
- return n;
-}
-
-
-// --===== mutations =====--
-
-function clamp(value, min, max) {
- if (value > max) { return max; }
- if (value < min) { return min; }
- return value;
-}
-
-// adjust the source input of a gene
-export function mut_gene_source(n_input, n_internal, n_output, gene, r) {
- const [source, sink, weight] = gene;
-
- const new_source = r < 0.5 ? source-1 : source+1;
-
- return [
- clamp(new_source, 0, n_input+n_internal-1),
- sink,
- weight,
- ];
-}
-
-
-// adjust the sink target of a gene
-export function mut_gene_sink(n_input, n_internal, n_output, gene, r) {
- const [source, sink, weight] = gene;
-
- const new_sink = r < 0.5 ? sink-1 : sink+1;
-
- return [
- source,
- clamp(new_sink, n_input+n_internal, n_input+n_internal+n_output-1),
- weight,
- ];
-}
-
-
-// modify a gene's weight
-// only adjusts the weight by performing a weighted average, so as to
-// more gently modify the generated net
-export function mut_gene_weight(weight_max, gene, r) {
- const [source, sink, weight] = gene;
-
- const rr = (2*r)-1;
- const move = weight_max * rr;
- const new_weight = (2*weight + move)/3;
-
- return [
- source,
- sink,
- clamp(new_weight, -weight_max, weight_max),
- ];
-}
-
-
-
-// expand the size of the neural net encoded by the genome
-// relabels internal indices so that there is one extra internal neuron
-export function mut_genome_expand(genome, r) {
- const expand_index = Math.floor(genome.n_internal * r) + genome.n_input;
- const new_genes = genome.genes.map(([source, sink, weight]) => [
- source >= expand_index ? source+1 : source,
- sink >= expand_index ? sink+1 : sink,
- weight,
- ]);
-
- return {
- ...genome,
- n_internal: genome.n_internal+1,
- genes: new_genes,
- };
-}
-
-
-// contract the size of the neural net encoded by the genome
-// relabels internal indices so that there is one less internal neuron
-export function mut_genome_contract(genome, r) {
- const { n_input, n_internal, n_output } = genome;
- const contract_idx = Math.floor(n_internal * r) + n_input;
-
- // decrement sources on the contract index too, to prevent invalid genomes
- const new_source = (source) => source >= contract_idx ? source-1 : source;
- // decrement sinks only after the contract index
- const new_sink = (sink) => sink > contract_idx ? sink-1 : sink;
-
- const new_genes = genome.genes.map(([source, sink, weight]) => [
- new_source(source),
- new_sink(sink),
- weight,
- ]);
-
- return {
- ...genome,
- n_internal: n_internal-1,
- genes: new_genes,
- };
-}
-
-
-// append a newly generated gene to the end of the genome
-export function mut_genome_insert(genome, weight_max, r1=Math.random(), r2=Math.random(), r3=Math.random()) {
- const { n_input, n_internal, n_output } = genome;
- const source = Math.floor((n_input + n_internal) * r1);
- const sink = Math.floor((n_internal + n_output) * r2) + n_input;
- const weight = weight_max * ((2*r3)-1);
-
- return {
- ...genome,
- genes: [...genome.genes, [source, sink, weight]],
- };
-}
-
-
-// delete a gene from the genome
-export function mut_genome_delete(genome, r) {
- const del_idx = Math.floor(r * genome.genes.length);
- const genes = genome.genes.filter((_, idx) => idx != del_idx);
- return { ...genome, genes };
-}
-
-
-function mut_gene(
- [n_input, n_internal, n_output, genome],
- weight_max, r1, r2, r3
-) {
- const gene_idx = Math.floor(genome.length * r1);
- const mod = random_choice(['source', 'sink', 'weight'], r2);
- let new_gene;
- if (mod == 'source') {
- new_gene = mut_gene_source(
- n_input, n_internal, n_output,
- genome[gene_idx],
- r3
- );
- } else if (mod == 'sink') {
- new_gene = mut_gene_sink(
- n_input, n_internal, n_output,
- genome[gene_idx],
- r3
- );
- } else {
- new_gene = mut_gene_weight(
- weight_max, genome[gene_idx], r3
- );
- }
-
- const new_genome = genome.map((gene, idx) => {
- if (idx == gene_idx) { return new_gene; }
- return gene;
- });
-
- return [
- n_input, n_internal, n_output, new_genome
- ];
-}
-
-
-export function mutate_genome(obj, weight_max) {
- const mut = random_choice([
- 'gene', 'gene', 'gene',
- 'gene', 'gene', 'gene',
- 'gene', 'gene', 'gene',
- 'insert', 'delete',
- 'insert', 'delete',
- 'expand', 'contract',
- ], Math.random());
-
- if (mut == 'gene') {
- return mut_gene(
- obj, weight_max,
- Math.random(), Math.random(), Math.random()
- );
- } else if (mut == 'insert') {
- return mut_genome_insert(
- obj, weight_max,
- Math.random(), Math.random(), Math.random()
- );
- } else if (mut == 'delete') {
- return mut_genome_delete(obj, Math.random());
- } else if (mut == 'expand') {
- return mut_genome_expand(obj, Math.random());
- } else if (mut == 'contract') {
- return mut_genome_contract(obj, Math.random());
- } else {
- throw new Error(`bad mut value: ${mut}`);
- }
-}
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