Home > Foresight Analytics Platform > Web Application and Desktop Application > Data Analysis and Building Reports > Time Series Analysis > Building Workbook > Creating and Setting Up Calculated Series > Setting Up Calculation Method Parameters > Transformations > Mathematical > Logarithms Difference
Tool interfaces in the web application and in the desktop application are identical, and differences in functionality are given in appropiate commments.
The method calculates the log difference of neighboring series points for a certain period (ln(x[t]/X[t-N])):
dlog PoP. Previous period.
dlog YoY. Corresponding period of the previous year.
dlog YTD. End of the previous year.
It is included in the group of functions that perform transformations on series.
After the method is applied, in the workbook, based on each selected series a calculated series with a name of the dlog<Period>(<Series_Name>[t])(<Series_Name>) type is created, containing the calculation results. For example:
See also:
Working with Calculated Series | Modeling Container: Transformations on Variables or Factors | IModelling.DLog | IModelling.DLogx
To apply the method
Transformations button on the Calculations ribbon tab.