Skip to contents

Calculate rolling linear slope

Source: R/analyse_peak_slope.R
rolling_slope.Rd

rolling_slope(): Compute rolling linear regression slopes within a local window along a numeric vector.

slope(): Calculate the linear regression slope of a numeric vector via the least-squares formula.

Usage

rolling_slope(
  x,
  t = seq_along(x),
  width = NULL,
  span = NULL,
  align = c("centre", "left", "right"),
  partial = FALSE,
  na.rm = FALSE,
  verbose = TRUE,
  ...,
  env = rlang::caller_env()
)

slope(x, t = seq_along(x), na.rm = FALSE, ..., env = rlang::caller_env())

Arguments

x

A numeric vector of the response variable.

t

An optional numeric vector of the predictor variable (e.g. time). Default is seq_along(x).

width

An integer defining the local window in number of samples around idx in which to perform the operation, according to align.

span

A numeric value defining the local window time span around idx in which to perform the operation, according to align. In units of time_channel or t.

align

Window alignment as "centre"/"center" (the default), "left", or "right". Where "left" is forward looking, and "right" is backward looking from the current sample.

partial

Logical; default is FALSE, only returns values where a full window of valid (non-NA) samples are available. If TRUE, ignores NA and processes available valid samples (see Details).

na.rm

Logical; default is FALSE, propagates any NAs to the returned vector. If TRUE, ignores NAs and processes available valid samples within the local window. May return errors or warnings. (see Details).

verbose

Logical. TRUE (default) will display, and FALSE will silence warnings and information messages helpful for troubleshooting. Global default can be set via options(mnirs.verbose = FALSE).

...

Additional arguments.

env

The calling environment or a defused call, used to report errors and warnings as coming from the user-facing function rather than the validator.

Value

rolling_slope() returns a numeric vector of rolling local slopes in units of x / t, the same length as x.

slope() returns a numeric slope value in units of x / t, or NA_real_ when insufficient valid observations are present.

Details

See peak_slope() for details on window specification (width, span, align), partial windows, and direction detection.

Additional arguments (...) accepted:

bypass_checks

Logical; if TRUE, skips input validation. Intended for internal use when checks have already been performed upstream.

min_obs

Integer; minimum number of valid observations required per window to return a slope. Derived from width or span, or 2L when partial = TRUE.

intercept

Logical; if TRUE, slope() also attaches the y-intercept as attr(slope_val, "intercept").

window_idx

Logical; if TRUE, the window bounds from compute_window_bounds() are attached as attr(slopes, "bounds").

See also

peak_slope()