loess.control {stats} | R Documentation

## Set Parameters for Loess

### Description

Set control parameters for `loess` fits.

### Usage

    loess.control(surface = c("interpolate", "direct"),
                  statistics = c("approximate", "exact", "none"),
                  trace.hat = c("exact", "approximate"),
                  cell = 0.2, iterations = 4, iterTrace = FALSE, ...)

### Arguments

`surface` | should the fitted surface be computed exactly (`"direct"`) or via interpolation from a kd tree? Can be abbreviated.
`statistics` | should the statistics be computed exactly, approximately or not at all? Exact computation can be very slow. Can be abbreviated.
`trace.hat` | Only for the (default) case `(surface = "interpolate", statistics = "approximate")`: should the trace of the smoother matrix be computed exactly or approximately? It is recommended to use the approximation for more than about 1000 data points. Can be abbreviated.
`cell` | if interpolation is used this controls the accuracy of the approximation via the maximum number of points in a cell in the kd tree. Cells with more than `floor(n*span*cell)` points are subdivided.
`iterations` | the number of iterations used in robust fitting, i.e. only if `family` is `"symmetric"`.
`iterTrace` | logical (or integer) determining if tracing information during the robust iterations (`iterations`>= 2) is produced.
`...` | further arguments which are ignored.

### Value

A list with components

`surface` |
`statistics` |
`trace.hat` |
`cell` |
`iterations` |
`iterTrace` |

with meanings as explained under ‘Arguments’.

### See Also

`loess`

[Package stats version 3.3.0 Index]