CreateForecast - Amazon Forecast

CreateForecast

Creates a forecast for each item in the TARGET_TIME_SERIES dataset that was used to train the predictor. This is known as inference. To retrieve the forecast for a single item at low latency, use the QueryForecast operation. To export the complete forecast into your Amazon Simple Storage Service (Amazon S3) bucket, use the CreateForecastExportJob operation.

The range of the forecast is determined by the ForecastHorizon value, which you specify in the CreatePredictor request. When you query a forecast, you can request a specific date range within the forecast.

To get a list of all your forecasts, use the ListForecasts operation.

Note

The forecasts generated by Amazon Forecast are in the same time zone as the dataset that was used to create the predictor.

For more information, see Generating Forecasts.

Note

The Status of the forecast must be ACTIVE before you can query or export the forecast. Use the DescribeForecast operation to get the status.

By default, a forecast includes predictions for every item (item_id) in the dataset group that was used to train the predictor. However, you can use the TimeSeriesSelector object to generate a forecast on a subset of time series. Forecast creation is skipped for any time series that you specify that are not in the input dataset. The forecast export file will not contain these time series or their forecasted values.

Request Syntax

{ "ForecastName": "string", "ForecastTypes": [ "string" ], "PredictorArn": "string", "Tags": [ { "Key": "string", "Value": "string" } ], "TimeSeriesSelector": { "TimeSeriesIdentifiers": { "DataSource": { "S3Config": { "KMSKeyArn": "string", "Path": "string", "RoleArn": "string" } }, "Format": "string", "Schema": { "Attributes": [ { "AttributeName": "string", "AttributeType": "string" } ] } } } }

Request Parameters

The request accepts the following data in JSON format.

ForecastName

A name for the forecast.

Type: String

Length Constraints: Minimum length of 1. Maximum length of 63.

Pattern: ^[a-zA-Z][a-zA-Z0-9_]*

Required: Yes

ForecastTypes

The quantiles at which probabilistic forecasts are generated. You can currently specify up to 5 quantiles per forecast. Accepted values include 0.01 to 0.99 (increments of .01 only) and mean. The mean forecast is different from the median (0.50) when the distribution is not symmetric (for example, Beta and Negative Binomial).

The default quantiles are the quantiles you specified during predictor creation. If you didn't specify quantiles, the default values are ["0.1", "0.5", "0.9"].

Type: Array of strings

Array Members: Minimum number of 1 item. Maximum number of 20 items.

Length Constraints: Minimum length of 2. Maximum length of 4.

Pattern: (^0?\.\d\d?$|^mean$)

Required: No

PredictorArn

The Amazon Resource Name (ARN) of the predictor to use to generate the forecast.

Type: String

Length Constraints: Maximum length of 256.

Pattern: arn:([a-z\d-]+):forecast:.*:.*:.+

Required: Yes

Tags

The optional metadata that you apply to the forecast to help you categorize and organize them. Each tag consists of a key and an optional value, both of which you define.

The following basic restrictions apply to tags:

  • Maximum number of tags per resource - 50.

  • For each resource, each tag key must be unique, and each tag key can have only one value.

  • Maximum key length - 128 Unicode characters in UTF-8.

  • Maximum value length - 256 Unicode characters in UTF-8.

  • If your tagging schema is used across multiple services and resources, remember that other services may have restrictions on allowed characters. Generally allowed characters are: letters, numbers, and spaces representable in UTF-8, and the following characters: + - = . _ : / @.

  • Tag keys and values are case sensitive.

  • Do not use aws:, AWS:, or any upper or lowercase combination of such as a prefix for keys as it is reserved for AWS use. You cannot edit or delete tag keys with this prefix. Values can have this prefix. If a tag value has aws as its prefix but the key does not, then Forecast considers it to be a user tag and will count against the limit of 50 tags. Tags with only the key prefix of aws do not count against your tags per resource limit.

Type: Array of Tag objects

Array Members: Minimum number of 0 items. Maximum number of 200 items.

Required: No

TimeSeriesSelector

Defines the set of time series that are used to create the forecasts in a TimeSeriesIdentifiers object.

The TimeSeriesIdentifiers object needs the following information:

  • DataSource

  • Format

  • Schema

Type: TimeSeriesSelector object

Required: No

Response Syntax

{ "ForecastArn": "string" }

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.

ForecastArn

The Amazon Resource Name (ARN) of the forecast.

Type: String

Length Constraints: Maximum length of 256.

Pattern: arn:([a-z\d-]+):forecast:.*:.*:.+

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

LimitExceededException

The limit on the number of resources per account has been exceeded.

HTTP Status Code: 400

ResourceAlreadyExistsException

There is already a resource with this name. Try again with a different name.

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: