g_fft_pow(G;S;O;X)

Returns the fast Fourier transform (FFT) power spectrum for each group

Syntax

g_fft_pow(G;S;O;X)

Input

Argument Type Description
G any A space- or comma-separated list of column names

Rows are in the same group if their values for all of the columns listed in G are the same.

If G is omitted, all rows are considered to be in the same group.

If any of the columns listed in G contain N/A, the N/A value is considered a valid grouping value.
S integer The name of a column in which every row evaluates to a 1 or 0, which determines whether or not that row is selected to be included in the calculation

If S is omitted, all rows will be considered by the function (subject to any prior row selections).

If any of the values in S are neither 1 nor 0, an error is returned.
O integer A space- or comma-separated list of column names that determine the row order within a particular group

If O is omitted, the order is the current display order of the table.

If any of the values in O are N/A, an error is returned.
X integer or decimal A column name

X is a numeric column denoting real data.

Return Value

For every row in each group defined by G (and for those rows where S=1, if specified), g_fft_pow returns a decimal number corresponding to the power spectrum of the data computed using FFT for each group.

Data to be Fourier-transformed should not contain any N/A. Any N/A in the data returns N/A as the result for the entire group.