Tableau 简明教程
Tableau - Forecasting
预测是预测度量的未来值。有许多用于预测的数学模型。Tableau 使用称为 exponential smoothing 的模型。在指数平滑中，最近的观察值比更早的观察值赋予更大的权重。这些模型捕捉到数据变化的趋势或季节性并将其推断到未来。预测结果还可以成为创建的可视化中的一项。
Forecasting is about predicting the future value of a measure. There are many mathematical models for forecasting. Tableau uses the model known as exponential smoothing. In exponential smoothing, recent observations are given relatively more weight than older observations. These models capture the evolving trend or seasonality of the data and extrapolate them into the future. The result of a forecast can also become a field in the visualization created.
Tableau 采用时间维度和度量字段来创建预测。
Tableau takes a time dimension and a measure field to create a forecast.
Creating a Forecast
使用 Sample-superstore，预测下一年销售额度量的值。为达到此目的，请按照以下步骤进行操作。
Using the Sample-superstore, forecast the value of the measure sales for next year. To achieve this objective, following are the steps.
Step 1 − 在列架中使用订单日期（年份），在行架中使用销售额来创建折线图。转到分析选项卡，如以下屏幕截图所示，然后在“模型”类别下单击“预测”。
Step 1 − Create a line chart with Order Date (Year) in the columns shelf and Sales in the Rows shelf. Go to the Analysis tab as shown in the following screenshot and click Forecast under Model category.
Step 2 − 完成上述步骤后，你将找到设置各种预测选项的选项。将“预测长度”选择为 2 年，并将“预测模型”保留为“自动”，如下图截图所示。
Step 2 − On completing the above step, you will find the option to set various options for forecast. Choose the Forecast Length as 2 years and leave the Forecast Model to Automatic as shown in the following screenshot.
单击确定，你将获得如以下截图所示的最终预测结果。
Click OK, and you will get the final forecast result as shown in the following screenshot.
