Apply Transform

Apply prebuilt economic transformations — year-over-year change, constant prices, per capita, % of GDP, seasonal adjustment and currency conversion.

The Apply Transform step applies prebuilt transformations to the data, and lets you combine several at once.

The options available depend on the frequency of the input data. A daily dataset offers rolling-window transforms; a monthly one offers seasonal adjustment and sum-last-12-months; a yearly one offers neither. Every frequency includes Original Variable, which keeps the untransformed column alongside the transformed ones.

Some transformations need reference data that Alphacast supplies automatically — inflation indices for constant prices, population for per capita, GDP series for % of GDP, and exchange rates for currency conversion. These require the dataset to carry a country entity so the right reference series can be matched.

Each transformation adds a new column named after the original plus the transformation’s internal key — EMBI Global Diversified Subindices - 30d_change. The original column is kept, so you can apply several transformations to the same variable and compare them side by side.

Daily data

Transformation	What it does
1 day change	Change against the previous day.
7 days change	Change against the same day one week earlier.
7 days average	Rolling mean over the last 7 days.
30 days change	Change against the same day 30 days earlier.
30 days average	Rolling mean over the last 30 days.
30 days average - Month over Month	Monthly change of the 30-day rolling mean.
30 days sum	Total over the last 30 days.
Month to Date Change	Change from the start of the current month to date.
Month to Date Sum	Total from the start of the current month to date.
Year to Date Change	Change from the start of the current year to date.
Year to Date Sum	Total from the start of the current year to date.
Currency conversion LCU / USD - daily	Converts local currency units to US dollars.
Currency conversion BCS / USD	Argentina only.

Monthly data

Transformation	What it does
Year over Year	Change against the same month one year earlier.
Month over Month	Change against the previous month.
Year over Year - 3 months moving average	Year-over-year change of the 3-month moving average.
12 months average	Rolling annual mean.
Sum last 12 months	Total over the previous twelve months.
Sum last 12 months - Year over Year	Year-over-year change of that rolling total.
Sum last 12 months - Month over Month	Monthly change of that rolling total.
Sum last 12 months - % of GDP	The rolling annual total as a share of GDP.
% of GDP	The variable as a share of Gross Domestic Product.
Constant prices	Removes the effect of inflation.
Constant prices - Year over Year	Year-over-year change in real terms.
Constant prices - Month over Month	Monthly change in real terms.
Constant prices - Year over Year - 3 months moving average	Real year-over-year change of the 3-month moving average.
Seasonally adjusted	Removes seasonal variation.
Seasonally adjusted - Month over Month	Monthly change of the seasonally adjusted series.
Constant prices - Seasonally adjusted	Both adjustments combined.
Constant prices - Seasonally adjusted - Month over Month	Monthly change of the real, seasonally adjusted series.
Per Capita	Divided by the country’s population.
Constant prices - Per Capita	Per capita in real terms.
Year to Date Change / Year to Date Sum	From the start of the current year to date.
Currency conversion LCU / USD - monthly	Converts to US dollars.
Currency conversion BCS / USD	Argentina only.

Quarterly data

Transformation	What it does
Year over Year	Change against the same quarter one year earlier.
Quarter over Quarter	Change against the previous quarter.
Sum last 4 quarters	Total over the previous four quarters.
4 quarters average	Rolling mean over the last four quarters.
% of GDP	The variable as a share of Gross Domestic Product.
Constant prices	Removes the effect of inflation.
Constant prices - Year over Year	Year-over-year change in real terms.
Seasonally adjusted	Removes seasonal variation.
Seasonally adjusted - Quarter over Quarter	Quarterly change of the seasonally adjusted series.
Per Capita	Divided by the country’s population.
Constant prices - Per Capita	Per capita in real terms.
Year to Date Change / Year to Date Sum	From the start of the current year to date.
Currency conversion LCU / USD - quarterly	Converts to US dollars.
Currency conversion BCS / USD	Argentina only.

Yearly data

Transformation	What it does
Year over Year	Change against the previous year.
Constant prices	Removes the effect of inflation.
Constant prices - Year over Year	Year-over-year change in real terms.
% of GDP	The variable as a share of Gross Domestic Product.
% of Current USD GDP	As a share of GDP measured in current US dollars.
Per Capita	Divided by the country’s population.
Constant prices - Per Capita	Per capita in real terms.
Currency conversion LCU / USD	Converts to US dollars.
Currency conversion BCS / USD	Argentina only.

For seasonal adjustment with control over the underlying model — including trend and irregular components — use the X13 ARIMA Seasonal Adjustment step rather than the prebuilt Seasonally adjusted transformation.

Country-specific unit conversions are also available on their own through the Apply Country Transform step. If none of the prebuilt options fit, Calculate Variable lets you write the transformation yourself — see the formula reference.

Next steps

Calculate variable

Write custom formulas when a prebuilt transform doesn’t fit.

Change frequency

Resample first to unlock frequency-specific transforms.