# plus-.fData: Operator '+' and '-' for 'fData' objects In roahd: Robust Analysis of High Dimensional Data

## Description

These methods provide operators `+` and `-` to perform sums or differences between an `fData` object and either another `fData` object or other compliant data structures, like matrices or vectors or arrays, representing the pointwise measurements of the second term of the sum.

## Usage

 ```1 2 3 4 5``` ```## S3 method for class 'fData' fD + A ## S3 method for class 'fData' fD - A ```

## Arguments

 `fD` the univariate functional dataset in form of `fData` object. `A` either an `fData` object, defined on the very same grid of `fD`, or a 1D data structure (such as 1D array or raw numeric vector), or a 2D data structure (such as 2D array or raw numeric matrix ), that specifies the second term of the sum. In case of a 1D data structure, the sum is performed element-wise between each element of `fD` and `A`, and `A` must have length `P`, size of `fD`'s grid. In case of a 2D data structure, the sum is performed element-wise between corresponding elements of `fD` and `A`'s rows. In this case, `A` must have `P` columns, as the size of `fD`'s grid.

## Details

If the second term of the operation is an `fData` object, it must be defined over the same grid as the first.

## Value

The function returns an `fData` object, whose function values have undergone the sum/difference.

## Examples

 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17``` ```fD = fData( seq( 0, 1, length.out = 10 ), values = matrix( seq( 1, 10 ), nrow = 21, ncol = 10, byrow = TRUE ) ) fD + 1 : 10 fD + array( 1, dim = c( 1, 10 ) ) fD + fD fD = fData( seq( 0, 1, length.out = 10 ), values = matrix( seq( 1, 10 ), nrow = 21, ncol = 10, byrow = TRUE ) ) fD - 2 : 11 fD - array( 1, dim = c( 1, 10 ) ) fD - fD ```

roahd documentation built on Aug. 24, 2020, 9:07 a.m.