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examples/numpy.js

@@ -57,29 +57,49 @@ const op = proxify(pymport('operator'));
   const a = np.array([20, 30, 40, 50]);
   const b = np.arange(4);
   console.log(b.toString());
+
+  // c = a - b
   const c = op.sub(a, b);
+
   console.log(c.toString());
+
+  // print(b ** 2)
   console.log(op.pow(b, 2).toString());
+
+  // print(10 * np.sin(a))
   console.log(op.mul(10, np.sin(a)).toString());
+
+  // print(a < 35)
   console.log(op.lt(a, 35).toString());
 
   const A = np.array([[1, 1], [0, 1]]);
   const B = np.array([[2, 0], [3, 4]]);
+
+  // print(A * B)
   console.log(op.mul(A, B).toString());
+
+  // print(A @ B)
   console.log(op.matmul(A, B).toString());
+
+  // print(A.dot(B))
   console.log(A.dot(B).toString());
 }
 
 const rg = np.random.default_rng(1);
 {
   const a = np.ones([2, 3], { dtype: np.int32 });
   const b = rg.random([2, 3]);
+
+  // a *= 3
   op.imul(a, 3);
   console.log(a.toString());
+
+  // b += a
   op.iadd(b, a);
   console.log(b.toString());
 
   try {
+    // a += b -> it throws
     op.iadd(a, b);
   } catch (e) {
     console.warn(e);
@@ -100,6 +120,9 @@ const rg = np.random.default_rng(1);
 {
   const a = rg.random([2, 3]);
   console.log(a.toString());
+
+  // a.sum() is a PyObject (Python reference) that contains a float
+  // a.sum().toJS() is a JS number
   console.log(a.sum().toJS());
   console.log(a.min().toJS());
   console.log(a.max().toJS());
@@ -108,8 +131,13 @@ const rg = np.random.default_rng(1);
 {
   const b = np.arange(12).reshape(3, 4);
   console.log(b.toString());
+
+  // print(b.sum(axis=0))
   console.log(b.sum({ axis: 0 }).toString());
+
+  // print(b.min(axis=1))
   console.log(b.min({ axis: 1 }).toString());
+
   console.log(b.cumsum({ axis: 1 }).toString());
 }
 
@@ -137,24 +165,29 @@ console.log('Indexing, Slicing and Iterating');
   a.__setitem__(PyObject.slice({ stop: 6, step: 2 }), 1000);
   console.log(a.toString());
 
+  // a[::-1]  # reversed a
   console.log(a.__getitem__(PyObject.slice({ step: -1 })).toString());
 
+  // numpy arrays are directly iterable in JavaScript
+  // every element is a PyObject
   for (const i of a) {
     console.log(op.pow(i, 1 / 3).toString());
   }
 }
 
 {
+  // Don't forget that this function will receive PyObject arguments
   const f = (x, y) => op.add(op.mul(10, x), y);
 
   const b = np.fromfunction(f, [5, 4], { dtype: np.int32 });
   console.log(b.toString());
 
-  // b[2, 3]
+  // b[2, 3] -> (2, 3) is a tuple which is a single argument to operator[]
   console.log(b.__getitem__(PyObject.tuple([2, 3])).toString());
 
   // b[0:5, 1]
   console.log(b.__getitem__(PyObject.tuple([PyObject.slice({ start: 0, stop: 5 }), 1])).toString());
 
+  // b[-1]
   console.log(b.__getitem__(-1).toString());
 }