Functional Contrast (Disease Suppression Profiles)

Calculates functional contrast curves (Disease Suppression Profiles - DSP) between a reference treatment (e.g., untreated control) and other fungicide treatments over time. The DSP is defined by default as: $$DSP(t) = y_{control}(t) - y_{treatment}(t)$$ where $y(t)$ is the disease intensity at time $t$. The goal is to evaluate the intensity, timing, and persistence of the fungicide protection.

Usage

functional_contrast(
  data,
  time = "time",
  response = "response",
  treatment = "treatment",
  reference = "Control",
  group = NULL,
  smooth = FALSE,
  grid = NULL,
  contrast = c("difference", "relative"),
  keep_reference = FALSE
)

Arguments

data: A data frame containing disease progress observations, or an object of class "functional_curves".
time: Character string naming the time variable.
response: Character string naming the response variable.
treatment: Character string naming the treatment variable.
reference: Character string specifying the reference treatment level. Default is "Control".
group: Optional character vector of grouping variables (e.g., c("experiment", "location")).
smooth: Logical; if TRUE, the function could apply smoothing (currently placeholder).
grid: Optional numeric vector of common time points for interpolation. If provided, curves are interpolated.
contrast: Character specifying the contrast type. Currently "difference" is implemented.
keep_reference: Logical; if TRUE, includes the reference treatment in the output (with DSP = 0). Default is FALSE.

Value

An object of class "functional_dsp" (inheriting from "tbl_df"), containing:

grouping variables (if any)
treatment variable
time variable
y_reference: disease intensity of the reference
y_treatment: disease intensity of the treatment
DSP: the computed contrast
contrast_type: type of contrast used
reference: name of the reference treatment

Usage

Arguments

Value

See also