Implement config.legacySubset

Author: dvd101x

AUTHORS

@@ -265,5 +265,6 @@ Christian Stussak <stussak@mfo.de>
 aitee <1228639+aitee@users.noreply.github.com>
 Delaney Sylvans <delaneysylvans@gmail.com>
 Rani D. <73716554+ranidam@users.noreply.github.com>
+Don McCurdy <dm@donmccurdy.com>
 
 # Generated by tools/update-authors.js

src/core/config.js

@@ -28,5 +28,11 @@ export const DEFAULT_CONFIG = {
 
   // random seed for seeded pseudo random number generation
   // null = randomly seed
-  randomSeed: null
+  randomSeed: null,
+
+  // legacy behavior for matrix subset, when false, the subset function
+  // return a matrix or array with the same size of the index (except for the scalar),
+  // when false returns a matrix or array with a size depending
+  // on the type of index
+  legacySubset: false
 }

src/core/function/config.js

@@ -61,6 +61,11 @@ export function configFactory (config, emit) {
         delete optionsFix.epsilon
         return _config(optionsFix)
       }
+
+      if (options.legacySubset === true) {
+        // this if is only for backwards compatibility, it can be removed in the future.
+        console.warn('Warning: The configuration option "legacySubset" is for compatibility only and might be deprecated in the future.')
+      }
       const prev = clone(config)
 
       // validate some of the options

src/function/algebra/sylvester.js

@@ -16,7 +16,8 @@ const dependencies = [
   'subtract',
   'identity',
   'lusolve',
-  'abs'
+  'abs',
+  'config'
 ]
 
 export const createSylvester = /* #__PURE__ */ factory(name, dependencies, (
@@ -35,7 +36,8 @@ export const createSylvester = /* #__PURE__ */ factory(name, dependencies, (
     subtract,
     identity,
     lusolve,
-    abs
+    abs,
+    config
   }
 ) => {
   /**

src/type/matrix/DenseMatrix.js

@@ -10,10 +10,11 @@ import { optimizeCallback } from '../../utils/optimizeCallback.js'
 
 const name = 'DenseMatrix'
 const dependencies = [
-  'Matrix'
+  'Matrix',
+  'config'
 ]
 
-export const createDenseMatrixClass = /* #__PURE__ */ factory(name, dependencies, ({ Matrix }) => {
+export const createDenseMatrixClass = /* #__PURE__ */ factory(name, dependencies, ({ Matrix, config }) => {
   /**
    * Dense Matrix implementation. A regular, dense matrix, supporting multi-dimensional matrices. This is the default matrix type.
    * @class DenseMatrix
@@ -218,7 +219,9 @@ export const createDenseMatrixClass = /* #__PURE__ */ factory(name, dependencies
       throw new TypeError('Invalid index')
     }
 
-    const isScalar = index.isScalar()
+    const isScalar = config.legacySubset
+      ? index.size().every(idx => idx === 1)
+      : index.isScalar()
     if (isScalar) {
       // return a scalar
       return matrix.get(index.min())
@@ -243,7 +246,7 @@ export const createDenseMatrixClass = /* #__PURE__ */ factory(name, dependencies
       returnMatrix._size = submatrix.size
       returnMatrix._datatype = matrix._datatype
       returnMatrix._data = submatrix.data
-      return returnMatrix
+      return config.legacySubset ? returnMatrix.reshape(index.size()) : returnMatrix
     }
   }
 
@@ -262,27 +265,27 @@ export const createDenseMatrixClass = /* #__PURE__ */ factory(name, dependencies
     return { data: getSubmatrixRecursive(data), size: size.filter(x => x !== null) }
 
     function getSubmatrixRecursive (data, depth = 0) {
-      const ranges = index.dimension(depth)
-      function _mapIndex (range, callback) {
+      const dims = index.dimension(depth)
+      function _mapIndex (dim, callback) {
         // applies a callback for when the index is a Number or a Matrix
-        if (isNumber(range)) return callback(range)
-        else return range.map(callback).valueOf()
+        if (isNumber(dim)) return callback(dim)
+        else return dim.map(callback).valueOf()
       }
 
-      if (isNumber(ranges)) {
+      if (isNumber(dims)) {
         size[depth] = null
       } else {
-        size[depth] = ranges.size()[0]
+        size[depth] = dims.size()[0]
       }
       if (depth < maxDepth) {
-        return _mapIndex(ranges, rangeIndex => {
-          validateIndex(rangeIndex, data.length)
-          return getSubmatrixRecursive(data[rangeIndex], depth + 1)
+        return _mapIndex(dims, dimIndex => {
+          validateIndex(dimIndex, data.length)
+          return getSubmatrixRecursive(data[dimIndex], depth + 1)
         })
       } else {
-        return _mapIndex(ranges, rangeIndex => {
-          validateIndex(rangeIndex, data.length)
-          return data[rangeIndex]
+        return _mapIndex(dims, dimIndex => {
+          validateIndex(dimIndex, data.length)
+          return data[dimIndex]
         })
       }
     }

test/unit-tests/core/config.test.js

@@ -37,4 +37,22 @@ describe('config', function () {
     // Restore console.warn
     warnStub.restore()
   })
+
+  it('should work with config legacySubset during deprecation', function () {
+    const math2 = math.create()
+    // Add a spy to temporarily disable console.warn
+    const warnStub = sinon.stub(console, 'warn')
+
+    // Set legacySubset to throw a warning
+    assert.doesNotThrow(function () { math2.config({ legacySubset: true }) })
+
+    // Check if legacySubset is set
+    assert.strictEqual(math2.config().legacySubset, true)
+
+    // Check if console.warn was called
+    assert.strictEqual(warnStub.callCount, 1)
+
+    // Restore console.warn
+    warnStub.restore()
+  })
 })