Javascript implementation of TriadicMemory, uses ndarray for implementation, uses Jest for some basic testing.

Author: callumhay

.gitignore

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+Javascript/coverage
+Javascript/node_modules

Javascript/.babelrc

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+{
+  "presets": [
+    ["@babel/preset-env"]
+  ],
+  "env": {
+    "test": {
+      "plugins": ["@babel/plugin-transform-modules-commonjs"]
+    }
+  }
+}

Javascript/SDRUtils.js

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+import ndarray from "ndarray";
+
+const ONE_HALF_MINUS_EPSILON = 0.5-Number.MIN_VALUE;
+
+class SDRUtils {
+  static buildLinearEncoderDecoder(minValue, maxValue, sdrSize, sdrWidth) {
+    return [
+      SDRUtils.buildLinearEncoder(minValue, maxValue, sdrSize, sdrWidth),
+      SDRUtils.buildLinearDecoder(minValue, maxValue, sdrSize, sdrWidth)
+    ];
+  }
+
+  static buildLinearEncoder(minValue, maxValue, sdrSize, sdrWidth) {
+    const bitRange = sdrSize-sdrWidth;
+    const valueRange = maxValue - minValue;
+    
+    return (value) => {
+      const firstBit = Math.floor(bitRange*(value-minValue)/valueRange + ONE_HALF_MINUS_EPSILON);
+      return SDRUtils.range(firstBit, firstBit+sdrWidth);
+    };
+  }
+
+  static buildLinearDecoder(minValue, maxValue, sdrSize, sdrWidth) {
+    const bitRange = sdrSize-sdrWidth;
+    const valueRange = maxValue - minValue;
+    return (sdr, rounded=true) => {
+      const decoded = (sdr[0]-ONE_HALF_MINUS_EPSILON)*valueRange/bitRange + minValue;
+      return rounded ? Math.round(decoded) : decoded;
+    }
+  }
+
+  static range(start, end, step=1) {
+    return Array.from(new Array(end-start), (_,i) => i*step + start);
+  }
+}
+
+export default SDRUtils;

Javascript/TriadicMemory.js

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+import ndarray from "ndarray";
+import ops from "ndarray-ops";
+
+class TriadicMemory {
+  constructor(n, p) {
+    this.mem = ndarray((new Uint8Array(n*n*n)).fill(0), [n,n,n]);
+    this.p = p;
+  }
+
+  get n() { return this.mem.shape[0]; }
+
+  store(x, y, z)  { TriadicMemory.storeXYZ(this.mem,x,y,z);  }
+  remove(x, y, z) { TriadicMemory.removeXYZ(this.mem,x,y,z); }
+
+  query(x, y, z=null) {
+    return (
+      z === null ? TriadicMemory.queryZ(this.mem,this.p,x,y) : (
+      x === null ? TriadicMemory.queryX(this.mem,this.p,y,z) :
+                   TriadicMemory.queryY(this.mem,this.p,x,z))
+    );
+  }
+
+  static storeXYZ(mem, x, y, z) {
+    for (const ax of x) {
+      for (const ay of y) {
+        for (const az of z) {
+          mem.set(ax,ay,az, mem.get(ax,ay,az)+1);
+        }
+      }
+    }
+  }
+
+  static removeXYZ(mem, x, y, z) {
+    for (const ax of x) {
+      for (const ay of y) {
+        for (const az of z) {
+          mem.set(ax,ay,az, Math.max(0,mem.get(ax,ay,az)-1));
+        }
+      }
+    }
+  }
+
+  static queryZ(mem, p, x, y) {
+    const n = mem.shape[0];
+    const sums = ndarray(new Uint32Array(n).fill(0));
+    for (const ax of x) {
+      for (const ay of y) {
+        ops.addeq(sums, mem.pick(ax,ay,null));
+      }
+    }
+    return TriadicMemory.sumsToSDR(sums.data, p);
+  }
+  static queryY(mem, p, x, z) {
+    const n = mem.shape[0];
+    const sums = ndarray(new Uint32Array(n).fill(0));
+    for (const ax of x) {
+      for (const az of z) {
+        ops.addeq(sums, mem.pick(ax,null,az));
+      }
+    }
+    return TriadicMemory.sumsToSDR(sums.data, p);
+  }
+  static queryX(mem, p, y, z) {
+    const n = mem.shape[0];
+    const sums = ndarray(new Uint32Array(n).fill(0));
+    for (const ay of y) {
+      for (const az of z) {
+        ops.addeq(sums, mem.pick(null,ay,az));
+      }
+    }
+    return TriadicMemory.sumsToSDR(sums.data, p);
+  }
+
+  /**
+   * Convert from an array of associative counters (sum) into a sparse, binary
+   * representation with a maximum number of 1s equal to p.
+   * @param {Array} sums 
+   * @param {Integer} p 
+   * @returns {Array} The sparse representation as an array of indicies into sums
+   * where the indicies i are all values where sums[i] >= the threshold defined by p.
+   */
+   static sumsToSDR(sums, p) {
+    const ssums = [...sums];
+    ssums.sort();
+    const sumsLen = ssums.length;
+    const threshold = Math.max(1, ssums[sumsLen-p]);
+    const result = [];
+    for (let i = 0; i < sumsLen; i++) {
+      if (sums[i] >= threshold) { result.push(i); }
+    }
+    return result;
+  }
+
+}
+
+export default TriadicMemory;

Javascript/jest.config.js

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+/*
+ * For a detailed explanation regarding each configuration property, visit:
+ * https://jestjs.io/docs/configuration
+ */
+
+module.exports = {
+  // All imported modules in your tests should be mocked automatically
+  // automock: false,
+
+  // Stop running tests after `n` failures
+  // bail: 0,
+
+  // The directory where Jest should store its cached dependency information
+  // cacheDirectory: "/private/var/folders/wc/wl4w92ts1978fq13g19708680000gn/T/jest_dx",
+
+  // Automatically clear mock calls, instances, contexts and results before every test
+  clearMocks: true,
+
+  // Indicates whether the coverage information should be collected while executing the test
+  collectCoverage: true,
+
+  // An array of glob patterns indicating a set of files for which coverage information should be collected
+  // collectCoverageFrom: undefined,
+
+  // The directory where Jest should output its coverage files
+  coverageDirectory: "coverage",
+
+  // An array of regexp pattern strings used to skip coverage collection
+  // coveragePathIgnorePatterns: [
+  //   "/node_modules/"
+  // ],
+
+  // Indicates which provider should be used to instrument code for coverage
+  // coverageProvider: "babel",
+
+  // A list of reporter names that Jest uses when writing coverage reports
+  // coverageReporters: [
+  //   "json",
+  //   "text",
+  //   "lcov",
+  //   "clover"
+  // ],
+
+  // An object that configures minimum threshold enforcement for coverage results
+  // coverageThreshold: undefined,
+
+  // A path to a custom dependency extractor
+  // dependencyExtractor: undefined,
+
+  // Make calling deprecated APIs throw helpful error messages
+  // errorOnDeprecated: false,
+
+  // The default configuration for fake timers
+  // fakeTimers: {
+  //   "enableGlobally": false
+  // },
+
+  // Force coverage collection from ignored files using an array of glob patterns
+  // forceCoverageMatch: [],
+
+  // A path to a module which exports an async function that is triggered once before all test suites
+  // globalSetup: undefined,
+
+  // A path to a module which exports an async function that is triggered once after all test suites
+  // globalTeardown: undefined,
+
+  // A set of global variables that need to be available in all test environments
+  // globals: {},
+
+  // The maximum amount of workers used to run your tests. Can be specified as % or a number. E.g. maxWorkers: 10% will use 10% of your CPU amount + 1 as the maximum worker number. maxWorkers: 2 will use a maximum of 2 workers.
+  // maxWorkers: "50%",
+
+  // An array of directory names to be searched recursively up from the requiring module's location
+  // moduleDirectories: [
+  //   "node_modules"
+  // ],
+
+  // An array of file extensions your modules use
+  // moduleFileExtensions: [
+  //   "js",
+  //   "mjs",
+  //   "cjs",
+  //   "jsx",
+  //   "ts",
+  //   "tsx",
+  //   "json",
+  //   "node"
+  // ],
+
+  // A map from regular expressions to module names or to arrays of module names that allow to stub out resources with a single module
+  // moduleNameMapper: {},
+
+  // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
+  // modulePathIgnorePatterns: [],
+
+  // Activates notifications for test results
+  // notify: false,
+
+  // An enum that specifies notification mode. Requires { notify: true }
+  // notifyMode: "failure-change",
+
+  // A preset that is used as a base for Jest's configuration
+  // preset: undefined,
+
+  // Run tests from one or more projects
+  // projects: undefined,
+
+  // Use this configuration option to add custom reporters to Jest
+  reporters: [
+    "default",
+  ],
+
+  // Automatically reset mock state before every test
+  // resetMocks: false,
+
+  // Reset the module registry before running each individual test
+  // resetModules: false,
+
+  // A path to a custom resolver
+  // resolver: undefined,
+
+  // Automatically restore mock state and implementation before every test
+  // restoreMocks: false,
+
+  // The root directory that Jest should scan for tests and modules within
+  // rootDir: undefined,
+
+  // A list of paths to directories that Jest should use to search for files in
+  // roots: [
+  //   "<rootDir>"
+  // ],
+
+  // Allows you to use a custom runner instead of Jest's default test runner
+  // runner: "jest-runner",
+
+  // The paths to modules that run some code to configure or set up the testing environment before each test
+  // setupFiles: [],
+
+  // A list of paths to modules that run some code to configure or set up the testing framework before each test
+  // setupFilesAfterEnv: [],
+
+  // The number of seconds after which a test is considered as slow and reported as such in the results.
+  // slowTestThreshold: 5,
+
+  // A list of paths to snapshot serializer modules Jest should use for snapshot testing
+  // snapshotSerializers: [],
+
+  // The test environment that will be used for testing
+  // testEnvironment: "jest-environment-node",
+
+  // Options that will be passed to the testEnvironment
+  // testEnvironmentOptions: {},
+
+  // Adds a location field to test results
+  // testLocationInResults: false,
+
+  // The glob patterns Jest uses to detect test files
+  testMatch: [
+    "**/tests/**/*.[jt]s?(x)"
+  ],
+
+  // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
+  // testPathIgnorePatterns: [
+  //   "/node_modules/"
+  // ],
+
+  // The regexp pattern or array of patterns that Jest uses to detect test files
+  // testRegex: [],
+
+  // This option allows the use of a custom results processor
+  // testResultsProcessor: undefined,
+
+  // This option allows use of a custom test runner
+  // testRunner: "jest-circus/runner",
+
+  // A map from regular expressions to paths to transformers
+  // transform: undefined,
+
+  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
+  // transformIgnorePatterns: [
+  //   "/node_modules/",
+  //   "\\.pnp\\.[^\\/]+$"
+  // ],
+
+  // An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
+  // unmockedModulePathPatterns: undefined,
+
+  // Indicates whether each individual test should be reported during the run
+  // verbose: undefined,
+
+  // An array of regexp patterns that are matched against all source file paths before re-running tests in watch mode
+  // watchPathIgnorePatterns: [],
+
+  // Whether to use watchman for file crawling
+  // watchman: true,
+};