Added tests for broadcasted subset in the parser

src/utils/array.js

@@ -775,7 +775,7 @@ export function broadcastTo (array, toSize) {
     Asize = arraySize(A)
   }
 
-  // stretches the arryas on each dimension to make them the same size
+  // stretches the array on each dimension to make it the same size as index
   for (let dim = 0; dim < N; dim++) {
     if (Asize[dim] < broadcastedSize[dim]) {
       A = stretch(A, broadcastedSize[dim], dim)
@@ -785,6 +785,25 @@ export function broadcastTo (array, toSize) {
   return A
 }
 
+/**
+ * Broadcasts arrays and returns the broadcasted arrays in an array
+ * @param  {...Array | any} arrays
+ * @returns
+ */
+export function broadcastArrays (...arrays) {
+  if (arrays.length === 0) {
+    throw new Error('Insuficient number of argumnets in function broadcastArrays')
+  }
+  if (arrays.length === 1) {
+    return arrays[0]
+  }
+  const sizes = arrays.map(function (array) { return arraySize(array) })
+  const broadcastedSize = broadcastSizes(...sizes)
+  const broadcastedArrays = []
+  arrays.forEach(function (array) { broadcastedArrays.push(broadcastTo(array, broadcastedSize)) })
+  return broadcastedArrays
+}
+
 /**
  * stretches a matrix up to a certain size in a certain dimension
  * @param {Array} arrayToStretch

test/unit-tests/expression/parse.test.js

@@ -689,6 +689,17 @@ describe('parse', function () {
       assert.deepStrictEqual(parseAndEval('a[2:end-1, 2:end-1]', scope), math.matrix([[2, 0], [9, 9]]))
     })
 
+    it('should get and set broadcasted submatrices in the parser', function () {
+      const scope = {}
+      parseAndEval('A = [1, 2, 3, 4]', scope)
+      assert.deepStrictEqual(parseAndEval('A[A>2]', scope), math.matrix([3, 4]))
+      parseAndEval('A[A>2] = 20', scope)
+      assert.deepStrictEqual(scope.A, math.matrix([1, 2, 20, 20]))
+      parseAndEval('A = [1, 2, 3, 4]', scope)
+      parseAndEval('A[A > 2] = [15]', scope)
+      assert.deepStrictEqual(scope.A, math.matrix([1, 2, 15, 15]))
+    })
+
     it('should merge nested matrices', function () {
       const scope = {}
       parseAndEval('a=[1,2;3,4]', scope)

test/unit-tests/utils/array.test.js

@@ -14,7 +14,8 @@ import {
   broadcastTo,
   concat,
   checkBroadcastingRules,
-  stretch
+  stretch,
+  broadcastArrays
 } from '../../../src/utils/array.js'
 
 describe('util.array', function () {
@@ -644,4 +645,17 @@ describe('util.array', function () {
       assert.throws(function () { checkBroadcastingRules([2, 2], [1, 2]) })
     })
   })
+
+  describe('broadcastArrays', function () {
+    it('should broadcast many arrays', function () {
+      assert.deepStrictEqual(broadcastArrays([1, 2], [3, 4]), [[1, 2], [3, 4]])
+      assert.deepStrictEqual(broadcastArrays([1, 2], [[3], [4]]), [[[1, 2], [1, 2]], [[3, 3], [4, 4]]])
+      assert.deepStrictEqual(broadcastArrays([1, 2], [[3], [4]], [5, 6]), [[[1, 2], [1, 2]], [[3, 3], [4, 4]], [[5, 6], [5, 6]]])
+    })
+    it('should throw an arryor when the broadcasting rules don\'t apply', function () {
+      assert.throws(function () { broadcastArrays([1, 2], [1, 2, 3]) })
+      assert.throws(function () { broadcastArrays([1, 2], [1, 2, 3], [4, 5]) })
+      assert.throws(function () { broadcastArrays([[1, 2], [1, 2]], [[1, 2, 3]]) })
+    })
+  })
 })