TimeSeriesCatalog.ForecastBySsa 方法
定义
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
单一频谱分析 (SSA) 模型进行单变量时序预测。 有关模型的详细信息,请参阅 http://arxiv.org/pdf/1206.6910.pdf。
public static Microsoft.ML.Transforms.TimeSeries.SsaForecastingEstimator ForecastBySsa (this Microsoft.ML.ForecastingCatalog catalog, string outputColumnName, string inputColumnName, int windowSize, int seriesLength, int trainSize, int horizon, bool isAdaptive = false, float discountFactor = 1, Microsoft.ML.Transforms.TimeSeries.RankSelectionMethod rankSelectionMethod = Microsoft.ML.Transforms.TimeSeries.RankSelectionMethod.Exact, int? rank = default, int? maxRank = default, bool shouldStabilize = true, bool shouldMaintainInfo = false, Microsoft.ML.Transforms.TimeSeries.GrowthRatio? maxGrowth = default, string confidenceLowerBoundColumn = default, string confidenceUpperBoundColumn = default, float confidenceLevel = 0.95, bool variableHorizon = false);
static member ForecastBySsa : Microsoft.ML.ForecastingCatalog * string * string * int * int * int * int * bool * single * Microsoft.ML.Transforms.TimeSeries.RankSelectionMethod * Nullable<int> * Nullable<int> * bool * bool * Nullable<Microsoft.ML.Transforms.TimeSeries.GrowthRatio> * string * string * single * bool -> Microsoft.ML.Transforms.TimeSeries.SsaForecastingEstimator
<Extension()>
Public Function ForecastBySsa (catalog As ForecastingCatalog, outputColumnName As String, inputColumnName As String, windowSize As Integer, seriesLength As Integer, trainSize As Integer, horizon As Integer, Optional isAdaptive As Boolean = false, Optional discountFactor As Single = 1, Optional rankSelectionMethod As RankSelectionMethod = Microsoft.ML.Transforms.TimeSeries.RankSelectionMethod.Exact, Optional rank As Nullable(Of Integer) = Nothing, Optional maxRank As Nullable(Of Integer) = Nothing, Optional shouldStabilize As Boolean = true, Optional shouldMaintainInfo As Boolean = false, Optional maxGrowth As Nullable(Of GrowthRatio) = Nothing, Optional confidenceLowerBoundColumn As String = Nothing, Optional confidenceUpperBoundColumn As String = Nothing, Optional confidenceLevel As Single = 0.95, Optional variableHorizon As Boolean = false) As SsaForecastingEstimator
参数
- catalog
- ForecastingCatalog
目录。
- outputColumnName
- String
转换 inputColumnName
生成的列的名称。
- inputColumnName
- String
要转换的列的名称。 如果设置为 null
,则 outputColumnName
的值将用作源。
向量包含警报、原始分数、P 值作为前三个值。
- windowSize
- Int32
序列上用于生成轨迹矩阵的窗口长度 (参数 L) 。
- seriesLength
- Int32
用于对参数 N) 进行建模的缓冲区中保留的序列长度 (。
- trainSize
- Int32
从开始开始用于训练的序列的长度。
- horizon
- Int32
要预测的值数。
- isAdaptive
- Boolean
确定模型是否自适应的标志。
- discountFactor
- Single
[0,1] 中用于联机更新的折扣因子。
- rankSelectionMethod
- RankSelectionMethod
排名选择方法。
用于 SSA 投影的子空间的所需排名 (参数 r) 。 此参数应位于 [1, windowSize] 中的范围内。 如果设置为 null,则根据预测误差最小化自动确定排名。
- shouldStabilize
- Boolean
确定是否应稳定模型的标志。
- shouldMaintainInfo
- Boolean
确定是否需要维护模型的元信息的标志。
- maxGrowth
- Nullable<GrowthRatio>
指数趋势的最大增长。
- confidenceLowerBoundColumn
- String
置信区间下限列的名称。 如果未指定,则不会计算置信区间。
- confidenceUpperBoundColumn
- String
置信区间上限列的名称。 如果未指定,则不会计算置信区间。
- confidenceLevel
- Single
预测的置信度。
- variableHorizon
- Boolean
如果在预测时间) 训练 (后,水平线将更改,请将此值设置为 true。
返回
示例
using System;
using System.Collections.Generic;
using System.IO;
using Microsoft.ML;
using Microsoft.ML.Transforms.TimeSeries;
namespace Samples.Dynamic
{
public static class Forecasting
{
// This example creates a time series (list of Data with the i-th element
// corresponding to the i-th time slot) and then does forecasting.
public static void Example()
{
// Create a new ML context, for ML.NET operations. It can be used for
// exception tracking and logging, as well as the source of randomness.
var ml = new MLContext();
// Generate sample series data with a recurring pattern.
var data = new List<TimeSeriesData>()
{
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
};
// Convert data to IDataView.
var dataView = ml.Data.LoadFromEnumerable(data);
// Setup arguments.
var inputColumnName = nameof(TimeSeriesData.Value);
var outputColumnName = nameof(ForecastResult.Forecast);
// Instantiate the forecasting model.
var model = ml.Forecasting.ForecastBySsa(outputColumnName,
inputColumnName, 5, 11, data.Count, 5);
// Train.
var transformer = model.Fit(dataView);
// Forecast next five values.
var forecastEngine = transformer.CreateTimeSeriesEngine<TimeSeriesData,
ForecastResult>(ml);
var forecast = forecastEngine.Predict();
Console.WriteLine($"Forecasted values:");
Console.WriteLine("[{0}]", string.Join(", ", forecast.Forecast));
// Forecasted values:
// [1.977226, 1.020494, 1.760543, 3.437509, 4.266461]
// Update with new observations.
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
// Checkpoint.
forecastEngine.CheckPoint(ml, "model.zip");
// Load the checkpointed model from disk.
// Load the model.
ITransformer modelCopy;
using (var file = File.OpenRead("model.zip"))
modelCopy = ml.Model.Load(file, out DataViewSchema schema);
// We must create a new prediction engine from the persisted model.
var forecastEngineCopy = modelCopy.CreateTimeSeriesEngine<
TimeSeriesData, ForecastResult>(ml);
// Forecast with the checkpointed model loaded from disk.
forecast = forecastEngineCopy.Predict();
Console.WriteLine("[{0}]", string.Join(", ", forecast.Forecast));
// [1.791331, 1.255525, 0.3060154, -0.200446, 0.5657795]
// Forecast with the original model(that was checkpointed to disk).
forecast = forecastEngine.Predict();
Console.WriteLine("[{0}]", string.Join(", ", forecast.Forecast));
// [1.791331, 1.255525, 0.3060154, -0.200446, 0.5657795]
}
class ForecastResult
{
public float[] Forecast { get; set; }
}
class TimeSeriesData
{
public float Value;
public TimeSeriesData(float value)
{
Value = value;
}
}
}
}
using System;
using System.Collections.Generic;
using System.IO;
using Microsoft.ML;
using Microsoft.ML.Transforms.TimeSeries;
namespace Samples.Dynamic
{
public static class ForecastingWithConfidenceInternal
{
// This example creates a time series (list of Data with the i-th element
// corresponding to the i-th time slot) and then does forecasting.
public static void Example()
{
// Create a new ML context, for ML.NET operations. It can be used for
// exception tracking and logging, as well as the source of randomness.
var ml = new MLContext();
// Generate sample series data with a recurring pattern.
var data = new List<TimeSeriesData>()
{
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
new TimeSeriesData(0),
new TimeSeriesData(1),
new TimeSeriesData(2),
new TimeSeriesData(3),
new TimeSeriesData(4),
};
// Convert data to IDataView.
var dataView = ml.Data.LoadFromEnumerable(data);
// Setup arguments.
var inputColumnName = nameof(TimeSeriesData.Value);
var outputColumnName = nameof(ForecastResult.Forecast);
// Instantiate the forecasting model.
var model = ml.Forecasting.ForecastBySsa(outputColumnName,
inputColumnName, 5, 11, data.Count, 5,
confidenceLevel: 0.95f,
confidenceLowerBoundColumn: "ConfidenceLowerBound",
confidenceUpperBoundColumn: "ConfidenceUpperBound");
// Train.
var transformer = model.Fit(dataView);
// Forecast next five values.
var forecastEngine = transformer.CreateTimeSeriesEngine<TimeSeriesData,
ForecastResult>(ml);
var forecast = forecastEngine.Predict();
PrintForecastValuesAndIntervals(forecast.Forecast, forecast
.ConfidenceLowerBound, forecast.ConfidenceUpperBound);
// Forecasted values:
// [1.977226, 1.020494, 1.760543, 3.437509, 4.266461]
// Confidence intervals:
// [0.3451088 - 3.609343] [-0.7967533 - 2.83774] [-0.058467 - 3.579552] [1.61505 - 5.259968] [2.349299 - 6.183623]
// Update with new observations.
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
forecastEngine.Predict(new TimeSeriesData(0));
// Checkpoint.
forecastEngine.CheckPoint(ml, "model.zip");
// Load the checkpointed model from disk.
// Load the model.
ITransformer modelCopy;
using (var file = File.OpenRead("model.zip"))
modelCopy = ml.Model.Load(file, out DataViewSchema schema);
// We must create a new prediction engine from the persisted model.
var forecastEngineCopy = modelCopy.CreateTimeSeriesEngine<
TimeSeriesData, ForecastResult>(ml);
// Forecast with the checkpointed model loaded from disk.
forecast = forecastEngineCopy.Predict();
PrintForecastValuesAndIntervals(forecast.Forecast, forecast
.ConfidenceLowerBound, forecast.ConfidenceUpperBound);
// [1.791331, 1.255525, 0.3060154, -0.200446, 0.5657795]
// Confidence intervals:
// [0.1592142 - 3.423448] [-0.5617217 - 3.072772] [-1.512994 - 2.125025] [-2.022905 - 1.622013] [-1.351382 - 2.482941]
// Forecast with the original model(that was checkpointed to disk).
forecast = forecastEngine.Predict();
PrintForecastValuesAndIntervals(forecast.Forecast,
forecast.ConfidenceLowerBound, forecast.ConfidenceUpperBound);
// [1.791331, 1.255525, 0.3060154, -0.200446, 0.5657795]
// Confidence intervals:
// [0.1592142 - 3.423448] [-0.5617217 - 3.072772] [-1.512994 - 2.125025] [-2.022905 - 1.622013] [-1.351382 - 2.482941]
}
static void PrintForecastValuesAndIntervals(float[] forecast, float[]
confidenceIntervalLowerBounds, float[] confidenceIntervalUpperBounds)
{
Console.WriteLine($"Forecasted values:");
Console.WriteLine("[{0}]", string.Join(", ", forecast));
Console.WriteLine($"Confidence intervals:");
for (int index = 0; index < forecast.Length; index++)
Console.Write($"[{confidenceIntervalLowerBounds[index]} -" +
$" {confidenceIntervalUpperBounds[index]}] ");
Console.WriteLine();
}
class ForecastResult
{
public float[] Forecast { get; set; }
public float[] ConfidenceLowerBound { get; set; }
public float[] ConfidenceUpperBound { get; set; }
}
class TimeSeriesData
{
public float Value;
public TimeSeriesData(float value)
{
Value = value;
}
}
}
}