# FourierBasis: Finds the Discrete Fourier Transformation Matrix In gmatt18/bcs: Bayesian Compressive Sensing Using Laplace Priors

## Description

Uses the package `fda` to find a transformation matrix where the columns are the different Fourier basis functions, evaluated at specified points along the rows of the matrix.

## Usage

 `1` ```FourierBasis(tlist, N, train = NULL) ```

## Arguments

 `tlist` an array of the specific points where the basis functions are evaluated at. `N` number of basis functions in the matrix. `train` indices corresponding to which rows of the matrix to keep. Default is to keep all rows.

## Value

A P x N discrete Fourier transformation matrix where P is equal to the length of `train` and N is the number of basis. If `train` is `NULL` then P equals the length of `tlist`.

## Examples

 ```1 2 3 4 5 6 7 8``` ```# Points to evaluate the basis functions at points <- c(0,1,2,3,4) # Find first 8 Fourier basis functions evaluted at "points" f <- FourierBasis(points, 8) # Find first 8 Fourier basis functions evaluated at "points" but only keep # last two rows f <- FourierBasis(points, 8, train = c(4,5)) ```

gmatt18/bcs documentation built on May 14, 2017, 12:56 p.m.