solutions update from 7ed0c61

100_Numpy_exercises_with_hints_with_solutions.md

@@ -566,9 +566,17 @@ for index in np.ndindex(Z.shape):
 
 ```python
 X, Y = np.meshgrid(np.linspace(-1, 1, 10), np.linspace(-1, 1, 10))
-D = np.sqrt(X*X+Y*Y)
 sigma, mu = 1.0, 0.0
-G = np.exp(-( (D-mu)**2 / ( 2.0 * sigma**2 ) ) )
+G = np.exp(-((X - mu) ** 2 + (Y - mu) ** 2) / (2.0 * sigma**2))
+print(G)
+
+# Another solution using the fact that a 2D Gaussian is separable
+# Author: Nin17
+x = np.linspace(-1, 1, 10)
+y = np.linspace(-1, 1, 10)
+gx = np.exp(-((x - mu) ** 2 / (2.0 * sigma**2)))
+gy = np.exp(-((y - mu) ** 2 / (2.0 * sigma**2)))
+G = gy[:, None] * gx[None, :]
 print(G)
 ```
 #### 57. How to randomly place p elements in a 2D array? (★★☆)

100_Numpy_exercises_with_solutions.md

@@ -566,9 +566,17 @@ for index in np.ndindex(Z.shape):
 
 ```python
 X, Y = np.meshgrid(np.linspace(-1, 1, 10), np.linspace(-1, 1, 10))
-D = np.sqrt(X*X+Y*Y)
 sigma, mu = 1.0, 0.0
-G = np.exp(-( (D-mu)**2 / ( 2.0 * sigma**2 ) ) )
+G = np.exp(-((X - mu) ** 2 + (Y - mu) ** 2) / (2.0 * sigma**2))
+print(G)
+
+# Another solution using the fact that a 2D Gaussian is separable
+# Author: Nin17
+x = np.linspace(-1, 1, 10)
+y = np.linspace(-1, 1, 10)
+gx = np.exp(-((x - mu) ** 2 / (2.0 * sigma**2)))
+gy = np.exp(-((y - mu) ** 2 / (2.0 * sigma**2)))
+G = gy[:, None] * gx[None, :]
 print(G)
 ```
 #### 57. How to randomly place p elements in a 2D array? (★★☆)

100_Numpy_random.ipynb

@@ -2,7 +2,7 @@
  "cells": [
   {
    "cell_type": "markdown",
-   "id": "a3747e86",
+   "id": "94b10be0",
    "metadata": {},
    "source": [
     "# 100 numpy exercises\n",
@@ -18,7 +18,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "8b9ef9a4",
+   "id": "1d0b9900",
    "metadata": {},
    "source": [
     "File automatically generated. See the documentation to update questions/answers/hints programmatically."
@@ -26,7 +26,7 @@
   },
   {
    "cell_type": "markdown",
-   "id": "792c1217",
+   "id": "21313ae9",
    "metadata": {},
    "source": [
     "Run the `initialise.py` module, then call a random question with `pick()` an hint towards its solution with\n",
@@ -36,7 +36,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "541f746c",
+   "id": "c4ad3a14",
    "metadata": {},
    "outputs": [],
    "source": [
@@ -46,7 +46,7 @@
   {
    "cell_type": "code",
    "execution_count": null,
-   "id": "d1743adb",
+   "id": "13bdf6d0",
    "metadata": {},
    "outputs": [],
    "source": [