Shape · Time series
Forecast
Forecasts the next periods of a measure from a dated series, one forecast per group, with a lower and upper band. It can also backtest the recent past to show how accurate the forecast would have been.
Also known as: Sales forecast, time-series projection
How it works
Choose Output: Forecast predicts the periods ahead, Backtest holds out the most recent periods and forecasts them from the rest. Pick optional Group by columns (one forecast per group), the Date column, the Value column, a Frequency (Auto-detect reads it from the gaps between dates) and the Horizon in periods, 6 by default; a backtest's Hold out follows the horizon unless set. Method Auto compares exponential smoothing against seasonal naive on a hold-out and keeps smoothing only when it wins. Interval is 80% or 95% (default). The input must be one row per period per group with no gaps, duplicates or NULLs; otherwise the node stops with a message naming the fix, usually Resample first. The output keeps the group, date and value columns and adds forecast, lower, upper and is_forecast; untick Include history rows to keep only the future rows. A backtest adds naive_forecast, method, error and abs_pct_error.
Inputs and outputs
Inputs
data— Table
Outputs
data— Table
Settings
The Attributes panel of Forecast, as in the app: the controls work, but nothing runs — there is no data behind it.
The same settings, as the Assistant writes them
{
dateColumn: string
valueColumn: string
groupBy?: string[]
frequency?: "auto"|"day"|"week"|"month"|"quarter"|"year"
horizon: number
method?: "auto"|"seasonal-naive"|"exponential-smoothing"
interval?: 80|95
includeHistory?: boolean
output?: "forecast"|"backtest"
holdOut?: number
}forecasts the next `horizon` periods of valueColumn, in units of `frequency` (3 months = frequency "month", horizon 3; "next quarter" of monthly data is horizon 3). groupBy gives one forecast per entity ("by region" = groupBy ["region"]). It needs ONE row per period per group — feed it the source directly and the plan adds the per-period totals itself. Output columns: the date, value and group columns plus forecast, lower, upper, is_forecast. Use output "backtest" with holdOut N when the goal asks how accurate a forecast would have been ("how well would we have forecast last quarter" = backtest, holdOut 3); its rows add naive_forecast, method, error, abs_pct_error. Use Forecast for any prediction of future values — never Code Gen or Linear Regression.
Example
Next quarter of monthly sales by region: date column month, value column sales, group by region, frequency Month, horizon 3. To see how well that would have worked last quarter, switch Output to Backtest with hold out 3.