Compute inverse FFT from FFT result.
Note that the output for this function could be complex values, so when doing calculation on data columns, you need to set column data type to complex prior to set column formula. For details, see the example section below.
vector<complex> invfft(vector<complex> cx)
Return the inverse FFT results.
//Set the data type of column A and B to complex in advance wks.col1.numerictype = 11; wks.col2.numerictype = 11; //Inverse FFT for complex vector vSignal, put result to column A col(A) = invfft(vSignal); //Returns the inverse FFT result for the shifted FFT complex result in column B. col(C) = invfft(ifftshift(col(B)))