R: FastFourierTransform(FFT)

hanaml.FFT {hana.ml.r}

R Documentation

FastFourierTransform(FFT)

Description

hanaml.FFT is a R wrapper for PAL fast-Fourier-transform.

Usage

hanaml.FFT(conn.context,
                                   data, key,
                                   num.type = NULL,
                                   inverse= NULL)

Arguments

`conn.context`	`ConnectionContext` Connection to SAP HANA System
`data`	`DataFrame` Dataset used for training the seasonality test model.
`key`	`character` ID column of data that indicates the order of the sequence.
`num.type`	`list of character, optional` Specify the number types(i.e. real or imaginary) of columns in data, e.g. num.type <- list(real = "COL1", imag = "COL2"), where "COL1" and "COL2" are assumed to be column names in data. If only one column is specified in num.type, only that column will be applied FFT. If not provided, then data must contain exactly 3 columns, and the two non-ID columns will be treated as real, imaginary part of data respectively.
`inverse`	`logical, optional` If FALSE, forward FFT is applied; otherwise inverse FFT is applied. Defaults to FALSE.

Value

DataFrame

ID: with same name and type as input data.
REAL: type DOUBLE, representing real part of the transformed sequence.
IMAG: type DOUBLE, representing imaginary part of the transformed sequence.

Examples

## Not run: 
> data$collect()
ID  RE   IM
0   1  2.0  9.0
1   2  3.0 -3.0
2   3  5.0  0.0
3   4  0.0  0.0
4   5 -2.0 -2.0
5   6 -9.0 -7.0
6   7  7.0  0.0
 Create fast Fourier Transform instance:
 > result <-  hanaml.FFT(conn.context, data, key = "ID")

 Perform fit on the given data:
 > result$Collect()
ID   REAL        IMAG
0   1   6.000000   -3.000000
1   2   16.273688  -0.900317
2   3  -5.393946    26.265112
3   4  -13.883222   18.514840
4   5  -4.233990   -2.947800
5   6   9.657319    3.189618
6   7   5.580151    21.878547

## End(Not run)

[Package hana.ml.r version 1.0.8 Index]