For large data, e.g. 2,000,000 rows of data, do Analysis: Signal Processing: FFT…
-->1,000,000 row data show in FFTResultData1 sheet.
In FFTResultData1 sheet, add a user column, F(x)=col(C).
In source data sheet, right click on row 1,400,000, and select set as end.
==>still existing 1,000,000 row data in result data sheet. it should be 700,000 row data.
Fixed in Origin2025b SR1