Exercise 22 corrected after rougier#67

Author: lexnekr

100_Numpy_exercises.ipynb

@@ -435,8 +435,7 @@
    "outputs": [],
    "source": [
     "Z = np.random.random((5,5))\n",
-    "Zmax, Zmin = Z.max(), Z.min()\n",
-    "Z = (Z - Zmin)/(Zmax - Zmin)\n",
+    "Z = (Z - np.mean (Z)) / (np.std (Z))\n",
     "print(Z)"
    ]
   },

100_Numpy_exercises.md

@@ -187,8 +187,7 @@ print(Z)
 
 ```python
 Z = np.random.random((5,5))
-Zmax, Zmin = Z.max(), Z.min()
-Z = (Z - Zmin)/(Zmax - Zmin)
+Z = (Z - np.mean (Z)) / (np.std (Z))
 print(Z)
 ```
 

100_Numpy_exercises_with_hint.ipynb

@@ -387,7 +387,7 @@
    "metadata": {},
    "source": [
     "#### 22. Normalize a 5x5 random matrix (★☆☆) \n",
-    "(**hint**: (x - min) / (max - min))"
+    "(**hint**: (x - mean) / std)"
    ]
   },
   {

100_Numpy_exercises_with_hint.md

@@ -145,7 +145,7 @@ np.nan - np.nan
 
 #### 22. Normalize a 5x5 random matrix (★☆☆) 
 
-(**hint**: (x - min) / (max - min))
+(**hint**: (x - mean) / std)