set default ptype to NULL

  stat = "identity",

  position = "identity",

  ...,

  ptype = plot_type(),

  ptype = NULL,

  ID = NULL,

  rasterize = FALSE,

  res = 100,

\alias{register_pairs_plot}

\title{Register pairs plot}

\usage{

register_pairs_plot(...)

register_pairs_plot(..., ptype = NULL, scale = list())

}

\arguments{

\item{...}{any valid layer parameters.}

\item{ptype}{a plot_type object, which can be created by `plot_type()`.}

\item{scale}{a list of aesthestic scale.}

}

\value{

set global options and return NULL.