From 261f715145c2dee67065b1de042a21adcb71092b Mon Sep 17 00:00:00 2001
From: Awin Huang <awinhuang@gmail.com>
Date: Thu, 9 Nov 2023 14:26:01 +0800
Subject: [PATCH] vault backup: 2023-11-09 14:26:01

---
 .obsidian/workspace.json                   | 12 ++++----
 05. 資料收集/Keras.tensorflow - shuffle.md | 34 ++++++++++++++++++++++
 2 files changed, 40 insertions(+), 6 deletions(-)
 create mode 100644 05. 資料收集/Keras.tensorflow - shuffle.md

diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 5f49a6e..82df01a 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -41,7 +41,7 @@
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                 "source": true
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@@ -114,7 +114,7 @@
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               "state": {
-                "file": "05. 資料收集/Keras.tensorflow - Dataset.md",
+                "file": "05. 資料收集/Keras.tensorflow - shuffle.md",
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@@ -139,7 +139,7 @@
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-                "file": "05. 資料收集/Keras.tensorflow - Dataset.md"
+                "file": "05. 資料收集/Keras.tensorflow - shuffle.md"
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           },
@@ -167,7 +167,7 @@
             "state": {
               "type": "file-properties",
               "state": {
-                "file": "05. 資料收集/Keras.tensorflow - Dataset.md"
+                "file": "05. 資料收集/Keras.tensorflow - shuffle.md"
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           }
@@ -212,6 +212,8 @@
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+    "05. 資料收集/Keras.tensorflow - Dataset.md",
+    "05. 資料收集/Keras.tensorflow - shuffle.md",
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     "01. 個人/01. Daily/2023-11-07(週二).md",
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@@ -238,11 +240,9 @@
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     "00. Inbox/台語諺語.md",
-    "05. 資料收集/99. templates/日記.md",
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diff --git a/05. 資料收集/Keras.tensorflow - shuffle.md b/05. 資料收集/Keras.tensorflow - shuffle.md
new file mode 100644
index 0000000..c522430
--- /dev/null
+++ b/05. 資料收集/Keras.tensorflow - shuffle.md	
@@ -0,0 +1,34 @@
+如果想用同時打亂x_train與y_train，可以參考這2個方法。
+
+## 1. 用 `tf.random.shuffle`
+```python
+indices = tf.range(start=0, limit=tf.shape(x_data)[0], dtype=tf.int32)
+idx = tf.random.shuffle(indices)
+x_data = tf.gather(x_data, idx)
+y_data = tf.gather(y_data, idx)
+```
+
+先建立一個跟array一樣大的list，然後打亂它，再用這個已打亂的list當作索引來建立一個新的data list。
+
+## 2. 
+```python
+x_train = tf.data.Dataset.from_tensor_slices(x)
+y_train = tf.data.Dataset.from_tensor_slices(y)
+
+x_train, y_train = x_train.shuffle(buffer_size=2, seed=2), y_train.shuffle(buffer_size=2, seed=2)
+dataset = tf.data.Dataset.from_tensor_slices((x_train, y_train))
+```
+
+或者
+
+```python
+BF = 2
+SEED = 2
+def shuffling(dataset, bf, seed_number):
+   return dataset.shuffle(buffer_size=bf, seed=seed_number)
+
+x_train, y_train = shuffling(x_train, BF, SEED), shuffling(y_train, BF, SEED)
+dataset = tf.data.Dataset.from_tensor_slices((x_train, y_train))
+```
+
+概念跟第一點是一樣的，但是這是先轉成 `tf.data.Dataset`，然後把x_train跟y_train都用同樣的seed打亂。
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