# Operator + and - for fData objects

### 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 |

`A` |
either an |

### 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
``` |