From 3db360b13b305026bf57d19c744fad126ca12509 Mon Sep 17 00:00:00 2001
From: Tiziano Zito <opossumnano@gmail.com>
Date: Tue, 20 Aug 2024 18:42:14 +0200
Subject: [PATCH] simplify puzzle notebook

---
 puzzle.ipynb | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/puzzle.ipynb b/puzzle.ipynb
index e8d2d75..ba24b00 100644
--- a/puzzle.ipynb
+++ b/puzzle.ipynb
@@ -32,10 +32,8 @@
     "# create a collection of time series\n",
     "# in real life, this data comes from an experiment/simulation\n",
     "n_series = 128\n",
-    "len_one_series = 2**15  # ➔ 2^15 = 32768 items (8 B x 2^15 = 262144 B = 256 K)\n",
-    "time_series = []\n",
-    "for idx in range(n_series):\n",
-    "    time_series.append(np.zeros((len_one_series,1), dtype='float64'))"
+    "len_one_series = 2**20  # ➔ 2^20 = 1,048,576 items (8 B x 2^20 = 8,388,608 B = 8 M)\n",
+    "time_series = np.zeros((n_series, len_one_series), dtype='float64')"
    ]
   },
   {
@@ -52,9 +50,10 @@
    "outputs": [],
    "source": [
     "# how much memory does one time series need?\n",
-    "ts_size = time_series[0].nbytes/2**10 # -> 2^10 is 1 K\n",
-    "print(f'Size of one time series: {int(ts_size)} K')\n",
-    "print(f'Size of collection: {int(n_series*ts_size/1024)} M')"
+    "ts_size = time_series[0].nbytes/2**20 # -> 2^20 is 1 M\n",
+    "total_size = time_series.nbytes/2**20\n",
+    "print(f'Size of one time series: {int(ts_size)} M')\n",
+    "print(f'Size of collection: {int(total_size)} M')"
    ]
   },
   {
@@ -112,7 +111,7 @@
    },
    "outputs": [],
    "source": [
-    "x = np.zeros((n_series, len_one_series, 1), dtype='float64')\n",
+    "x = np.zeros((n_series, len_one_series), dtype='float64')\n",
     "%timeit load_data_row(x, time_series)"
    ]
   },
@@ -129,7 +128,7 @@
    },
    "outputs": [],
    "source": [
-    "x = np.zeros((len_one_series, n_series, 1), dtype='float64')\n",
+    "x = np.zeros((len_one_series, n_series), dtype='float64')\n",
     "%timeit load_data_column(x, time_series)"
    ]
   },
@@ -139,7 +138,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "# on my machine: 2.2 ms vs 33.9 ms ≈ 15x slowdown!!!"
+    "# on my machine: 31 ms vs 1240 ms ≈ 40x slowdown!!!"
    ]
   }
  ],
@@ -159,7 +158,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.12.4"
+   "version": "3.12.5"
   },
   "nteract": {
    "version": "0.28.0"