R: Trim head and/or tail of a spectrum

trim_wl {photobiology} | R Documentation

## Trim head and/or tail of a spectrum

### Description

Trim head and tail of a spectrum based on wavelength limits, with interpolation at range boundaries used by default. Expansion is also possible.

### Usage

    trim_wl(x, range, use.hinges, fill, ...)

    ## Default S3 method:
    trim_wl(x, range, use.hinges, fill, ...)

    ## S3 method for class 'generic_spct'
    trim_wl(x, range = NULL, use.hinges = TRUE,
      fill = NULL, ...)

    ## S3 method for class 'generic_mspct'
    trim_wl(x, range = NULL, use.hinges = TRUE,
      fill = NULL, ..., .parallel = FALSE, .paropts = NULL)

    ## S3 method for class 'waveband'
    trim_wl(x, range = NULL, use.hinges = TRUE,
      fill = NULL, trim = getOption("photobiology.waveband.trim", default =
      TRUE), ...)

    ## S3 method for class 'list'
    trim_wl(x, range = NULL, use.hinges = TRUE, fill = NULL,
      trim = getOption("photobiology.waveband.trim", default = TRUE), ...)

### Arguments

`x` | an R object.
`range` | a numeric vector of length two, or any other object for which function range() will return two.
`use.hinges` | logical Flag indicating whether to insert "hinges" into the spectral data before integration so as to reduce interpolation errors at the boundaries of the wavebands.
`fill` | if `fill == NULL` then tails are deleted, otherwise tails are filled with the value of fill.
`...` | ignored (possibly used by derived methods).
`.parallel` | if TRUE, apply function in parallel, using parallel backend provided by foreach
`.paropts` | a list of additional options passed into the foreach function when parallel computation is enabled. This is important if (for example) your code relies on external data or packages: use the .export and .packages arguments to supply them so that all cluster nodes have the correct environment set up for computing.
`trim` | logical (default is TRUE which trims the wavebands at the boundary, while FALSE discards wavebands that are partly off-boundary).

### Value

A copy of `x`, usually trimmed or expanded to a different length, either shorter or longer. Possibly with some of the original spectral data values replaced with `fill`.

### Methods (by class)

- `default`: Default for generic function

- `generic_spct`: Trim an object of class "generic_spct" or derived.

- `generic_mspct`: Trim an object of class "generic_mspct" or derived.

- `waveband`: Trim an object of class "waveband".

- `list`: Trim a list (of "waveband" objects).

### Note

By default the `w.length` values for the first and last rows in the returned object are the values supplied as `range`.

trim_wl when applied to waveband objects always inserts hinges when trimming.

trim_wl when applied to waveband objects always inserts hinges when trimming.

### See Also

Other trim functions: `clip_wl`, `trim_spct`, `trim_waveband`

### Examples

    trim_wl(sun.spct, range = c(400, 500))
    trim_wl(sun.spct, range = c(NA, 500))
    trim_wl(sun.spct, range = c(400, NA))

[Package photobiology version 0.9.21 Index]