plot.IWTlm: Plot method for IWT results on functional on scalar linear...

In alessiapini/fdatest: Interval Wise Testing for Functional Data

Plot method for IWT results on functional on scalar linear model

Description

plot method for class "IWTlm". Plotting function creating a graphical output of the IWT for the test on a functional on scalar linear model: functional data, and IWT-adjusted p-values of the F-tests on the whole model and of t-tests on all covariates' effects.

Usage

## S3 method for class 'IWTlm'
plot(
  x,
  xrange = c(0, 1),
  alpha1 = 0.05,
  alpha2 = 0.01,
  plot_adjpval = FALSE,
  col = c(1, grDevices::rainbow(dim(x$adjusted_pval_part)[1])),
  ylim = NULL,
  ylab = "Functional Data",
  main = NULL,
  lwd = 1,
  type = "l",
  ...
)

## S3 method for class 'TWTlm'
plot(
  x,
  xrange = c(0, 1),
  alpha1 = 0.05,
  alpha2 = 0.01,
  plot_adjpval = FALSE,
  col = c(1, grDevices::rainbow(dim(x$adjusted_pval_part)[1])),
  ylim = NULL,
  ylab = "Functional Data",
  main = NULL,
  lwd = 1,
  type = "l",
  ...
)

Arguments

x	The object to be plotted. An object of class "IWTlm", usually, a result of a call to IWTlm.
xrange	Range of the x axis.
alpha1	First level of significance used to select and display significant effects. Default is alpha1 = 0.05.
alpha2	Second level of significance used to select and display significant effects. Default is alpha1 = 0.01. alpha1 and alpha2 are s.t. alpha2 < alpha1. Otherwise the two values are switched.
plot_adjpval	A logical indicating wether the plots of adjusted p-values have to be done. Default is plot_adjpval = FALSE.
col	Colors for the plot of functional data. Default is col = 1.
ylim	Range of the y axis. Default is NULL, giving a plot with authomatic range for functional data.
ylab	Label of y axis of the plot of functional data. Default is "Functional Data".
main	An overall title for the plots (it will be pasted to "Functional Data and F-test" for the first plot and to covariates names for the other plots).
lwd	Line width for the plot of the adjusted p-value function. Default is lwd=1.
type	line type for the plot of the adjusted p-value function. Default is type='l'.
...	Additional plotting arguments that can be used with function plot, such as graphical parameters (see par).

Value

No value returned. The function produces a graphical output of the IWT results: the plot of the functional data and the one of the adjusted p-values. The portions of the domain selected as significant by the test at level alpha1 and alpha2 are highlighted in the plot of the adjusted p-value function and in the one of functional data by gray areas (light and dark gray, respectively). The first plot reports the gray areas corresponding to a significant F-test on the whole model. The remaining plots report the gray areas corresponding to significant t-tests on each covariate's effect.

References

Pini, A., & Vantini, S. (2017). Interval-wise testing for functional data. Journal of Nonparametric Statistics, 29(2), 407-424.

Pini, A., Vantini, S., Colosimo, B. M., & Grasso, M. (2018). Domain‐selective functional analysis of variance for supervised statistical profile monitoring of signal data. Journal of the Royal Statistical Society: Series C (Applied Statistics) 67(1), 55-81.

Abramowicz, K., Hager, C. K., Pini, A., Schelin, L., Sjostedt de Luna, S., & Vantini, S. (2018). Nonparametric inference for functional‐on‐scalar linear models applied to knee kinematic hop data after injury of the anterior cruciate ligament. Scandinavian Journal of Statistics 45(4), 1036-1061.

See Also

IWTimage for the plot of p-values heatmaps. See also IWT1, IWT2 to perform the ITP to test on the mean of one population and test of differences between two populations. See ITPlmbspline for functional on scalar linear model based on B-spline basis representation.

Examples

# Importing the NASA temperatures data set
data(NASAtemp)

temperature <- rbind(NASAtemp$milan, NASAtemp$paris)
groups <- c(rep(0, 22), rep(1, 22))

# Performing the IWT
IWT.result <- IWTlm(temperature ~ groups, B = 2L)

# Summary of the IWT results
summary(IWT.result)

# Plot of the IWT results
layout(1)
plot(IWT.result)

# All graphics on the same device
layout(matrix(1:4, nrow = 2, byrow = FALSE))
plot(
  IWT.result, 
  main = 'NASA data', 
  plot_adjpval = TRUE, 
  xlab = 'Day', 
  xrange = c(1, 365)
)

alessiapini/fdatest documentation built on Jan. 4, 2025, 5:37 a.m.