Amazon Forecast is no longer available to new customers. Existing customers of Amazon Forecast can continue to use the service as normal. [Learn more"](https://aws.amazon.com/blogs/machine-learning/transition-your-amazon-forecast-usage-to-amazon-sagemaker-canvas/)
# GetAccuracyMetrics
Provides metrics on the accuracy of the models that were trained by the [CreatePredictor](API_CreatePredictor.md) operation. Use metrics to see how well the model performed and to decide whether to use the predictor to generate a forecast. For more information, see [Predictor Metrics](https://docs.aws.amazon.com/forecast/latest/dg/metrics.html).
**Important**
Amazon Forecast is no longer available to new customers. Existing customers of Amazon Forecast can continue to use the service as normal. [Learn more"](http://aws.amazon.com/blogs/machine-learning/transition-your-amazon-forecast-usage-to-amazon-sagemaker-canvas/)
This operation generates metrics for each backtest window that was evaluated. The number of backtest windows (`NumberOfBacktestWindows`) is specified using the [EvaluationParameters](API_EvaluationParameters.md) object, which is optionally included in the `CreatePredictor` request. If `NumberOfBacktestWindows` isn't specified, the number defaults to one.
The parameters of the `filling` method determine which items contribute to the metrics. If you want all items to contribute, specify `zero`. If you want only those items that have complete data in the range being evaluated to contribute, specify `nan`. For more information, see [FeaturizationMethod](API_FeaturizationMethod.md).
**Note**
Before you can get accuracy metrics, the `Status` of the predictor must be `ACTIVE`, signifying that training has completed. To get the status, use the [DescribePredictor](API_DescribePredictor.md) operation.
## Request Syntax
```
{
"PredictorArn": "string"
}
```
## Request Parameters
The request accepts the following data in JSON format.
** [PredictorArn](#API_GetAccuracyMetrics_RequestSyntax) **
The Amazon Resource Name (ARN) of the predictor to get metrics for.
Type: String
Length Constraints: Maximum length of 256.
Pattern: `arn:([a-z\d-]+):forecast:.*:.*:.+`
Required: Yes
## Response Syntax
```
{
"AutoMLOverrideStrategy": "string",
"IsAutoPredictor": boolean,
"OptimizationMetric": "string",
"PredictorEvaluationResults": [
{
"AlgorithmArn": "string",
"TestWindows": [
{
"EvaluationType": "string",
"ItemCount": number,
"Metrics": {
"AverageWeightedQuantileLoss": number,
"ErrorMetrics": [
{
"ForecastType": "string",
"MAPE": number,
"MASE": number,
"RMSE": number,
"WAPE": number
}
],
"RMSE": number,
"WeightedQuantileLosses": [
{
"LossValue": number,
"Quantile": number
}
]
},
"TestWindowEnd": number,
"TestWindowStart": number
}
]
}
]
}
```
## Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The following data is returned in JSON format by the service.
** [AutoMLOverrideStrategy](#API_GetAccuracyMetrics_ResponseSyntax) **
The `LatencyOptimized` AutoML override strategy is only available in private beta. Contact AWS Support or your account manager to learn more about access privileges.
The AutoML strategy used to train the predictor. Unless `LatencyOptimized` is specified, the AutoML strategy optimizes predictor accuracy.
This parameter is only valid for predictors trained using AutoML.
Type: String
Valid Values: `LatencyOptimized | AccuracyOptimized`
** [IsAutoPredictor](#API_GetAccuracyMetrics_ResponseSyntax) **
Whether the predictor was created with [CreateAutoPredictor](API_CreateAutoPredictor.md).
Type: Boolean
** [OptimizationMetric](#API_GetAccuracyMetrics_ResponseSyntax) **
The accuracy metric used to optimize the predictor.
Type: String
Valid Values: `WAPE | RMSE | AverageWeightedQuantileLoss | MASE | MAPE`
** [PredictorEvaluationResults](#API_GetAccuracyMetrics_ResponseSyntax) **
An array of results from evaluating the predictor.
Type: Array of [EvaluationResult](API_EvaluationResult.md) objects
## Errors
** InvalidInputException **
We can't process the request because it includes an invalid value or a value that exceeds the valid range.
HTTP Status Code: 400
** ResourceInUseException **
The specified resource is in use.
HTTP Status Code: 400
** ResourceNotFoundException **
We can't find a resource with that Amazon Resource Name (ARN). Check the ARN and try again.
HTTP Status Code: 400
## See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following:
+ [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/forecast-2018-06-26/GetAccuracyMetrics)
+ [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/forecast-2018-06-26/GetAccuracyMetrics)