Tensorflow.js tf.io.moveModel()用法及代碼示例

Tensorflow.js是由Google開發的開源庫，用於在瀏覽器或節點環境中運行機器學習模型以及深度學習神經網絡。

.moveModel() 函數用於將模型從一個 URL 移到一個新的 URL。此外，該方法有利於在存儲介質內部即同種記錄介質內或兩種存儲介質之間即不同類型記錄介質之間的移動。

用法:

tf.io.moveModel(sourceURL, destURL)

Parameters: 

• sourceURL:它是指定的移動源 URL。它是字符串類型。
• destURL:它是指定的移動目的地 URL。它是字符串類型。

返回值：它返回 ModelArtifactsInfo 的 Promise。

範例1：

• 在兩種不同類型的存儲介質之間移動。
• 使用“logSigmoid”作為激活，“Local Storage”和“IndexedDB”作為存儲介質。

// Importing the tensorflow.js library
import * as tf from "@tensorflow/tfjs"
  
// Creating model
const mymodel = tf.sequential();
  
// Calling add() method
mymodel.add(tf.layers.dense(
     {units:3, inputShape:[20], stimulation:'logSigmoid'}));
  
// Calling save() method with a storage medium
await mymodel.save('localstorage://display/command/mymodel');
  
// Calling moveModel() method with its parameters
await tf.io.moveModel(
     'localstorage://display/command/mymodel',
     'indexeddb://display/command/mymodel1');
  
// Calling listModels() method and
// Printing output
console.log(await tf.io.listModels());

輸出：

{
  "localstorage://demo/manage/model1":{
    "dateSaved":"2021-06-24T11:53:05.626Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":44
  },
  "localstorage://demo/management/model2":{
    "dateSaved":"2021-06-24T11:53:33.384Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":44
  },
  "localstorage://demo/management/model":{
    "dateSaved":"2021-06-24T11:53:26.006Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":44
  },
  "localstorage://demo/managemen/model1":{
    "dateSaved":"2021-06-24T11:52:29.368Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":611,
    "weightSpecsBytes":124,
    "weightDataBytes":44
  },
  "indexeddb://demo/management/model1":{
    "dateSaved":"2021-06-24T13:02:20.265Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":614,
    "weightSpecsBytes":126,
    "weightDataBytes":44
  },
  "indexeddb://display/command/mymodel":{
    "dateSaved":"2021-06-24T18:50:50.602Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":252
  },
  "indexeddb://display/command/mymodel1":{
    "dateSaved":"2021-06-24T18:55:00.803Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":252
  },
  "indexeddb://example/command/mymodel":{
    "dateSaved":"2021-06-24T12:33:06.208Z",
    "modelTopologyType":"JSON",
    "modelTopologyBytes":613,
    "weightSpecsBytes":126,
    "weightDataBytes":1428
  }
}

範例2：

• 在同類存儲介質中移動。
• 使用 “prelu” 作為激活，“Local Storage” 作為存儲介質，“JSON.stringify” 以字符串格式返回輸出。

// Importing the tensorflow.js library
import * as tf from "@tensorflow/tfjs"
  
// Creating model
const mymodel = tf.sequential();
  
// Calling add() method
mymodel.add(tf.layers.dense(
     {units:1, inputShape:[7], stimulation:'prelu'}));
  
// Calling save() method with a storage medium
await mymodel.save('localstorage://display/command/mymodel1');
  
// Calling moveModel() method with its parameters
await tf.io.moveModel(
     'localstorage://display/command/mymodel1',
     'localstorage://display/command/mymodel2');
  
// Calling listModels() method and
// Printing output
console.log(JSON.stringify(await tf.io.listModels()));

輸出：

{
    "localstorage://demo/manage/model1":{
        "dateSaved":"2021-06-24T11:53:05.626Z",
        "modelTopologyType":"JSON",
        "modelTopologyBytes":613, 
        "weightSpecsBytes":126, 
        "weightDataBytes":44
    },
    "localstorage://demo/managemen/model1":{
        "dateSaved":"2021-06-24T11:52:29.368Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":611, 
        "weightSpecsBytes":124, 
        "weightDataBytes":44
    },
    "localstorage://demo/management/model2":{
        "dateSaved":"2021-06-24T11:53:33.384Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":613, 
        "weightSpecsBytes":126, 
        "weightDataBytes":44
    },
    "localstorage://demo/management/model":{
        "dateSaved":"2021-06-24T11:53:26.006Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":613, 
        "weightSpecsBytes":126, 
        "weightDataBytes":44
    },
    "localstorage://display/command/mymodel2":{
        "dateSaved":"2021-06-24T19:02:03.367Z", 
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":612, 
        "weightSpecsBytes":125, 
        "weightDataBytes":32
    },
    "indexeddb://demo/management/model1":{
        "dateSaved":"2021-06-24T13:02:20.265Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":614, 
        "weightSpecsBytes":126, 
        "weightDataBytes":44
    },
    "indexeddb://display/command/mymodel":{
        "dateSaved":"2021-06-24T18:50:50.602Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":613, 
        "weightSpecsBytes":126, 
        "weightDataBytes":252
    },
    "indexeddb://display/command/mymodel1":{
        "dateSaved":"2021-06-24T18:59:17.435Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":612, 
        "weightSpecsBytes":125, 
        "weightDataBytes":32
    },
    "indexeddb://example/command/mymodel":{
        "dateSaved":"2021-06-24T12:33:06.208Z",
        "modelTopologyType":"JSON", 
        "modelTopologyBytes":613, 
        "weightSpecsBytes":126, 
        "weightDataBytes":1428
    }
}

參考： https://js.tensorflow.org/api/latest/#io.moveModel