% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/ddbs_affine.R
\name{ddbs_scale}
\alias{ddbs_scale}
\title{Scale geometries by X and Y factors}
\usage{
ddbs_scale(
  x,
  x_scale = 1,
  y_scale = 1,
  by_feature = FALSE,
  conn = NULL,
  name = NULL,
  mode = NULL,
  overwrite = FALSE,
  quiet = FALSE
)
}
\arguments{
\item{x}{Input spatial data. Can be:
\itemize{
\item A \code{duckspatial_df} object (lazy spatial data frame via dbplyr)
\item An \code{sf} object
\item A \code{tbl_lazy} from dbplyr
\item A character string naming a table/view in \code{conn}
}
Data is returned from this object.}

\item{x_scale}{numeric value specifying the scaling factor in the X direction (default = 1)}

\item{y_scale}{numeric value specifying the scaling factor in the Y direction (default = 1)}

\item{by_feature}{Logical. If \code{TRUE}, the geometric operation is applied
separately to each geometry. If \code{FALSE}, the geometric
operation is applied to the data as a whole.}

\item{conn}{A connection object to a DuckDB database. If \code{NULL}, the function
runs on a temporary DuckDB database.}

\item{name}{A character string of length one specifying the name of the table,
or a character string of length two specifying the schema and table
names. If \code{NULL} (the default), the function returns the result as an
\code{sf} object}

\item{mode}{Character. Controls the return type. Options:
\itemize{
\item \code{"duckspatial"} (default): Lazy spatial data frame backed by dbplyr/DuckDB
\item \code{"sf"}: Eagerly collected sf object (uses memory)
}
Can be set globally via \code{\link{ddbs_options}(mode = "...")} or
per-function via this argument. Per-function overrides global setting.}

\item{overwrite}{Boolean. whether to overwrite the existing table if it exists. Defaults
to \code{FALSE}. This argument is ignored when \code{name} is \code{NULL}.}

\item{quiet}{A logical value. If \code{TRUE}, suppresses any informational messages.
Defaults to \code{FALSE}.}
}
\value{
Depends on the \code{mode} argument (or global preference set by \code{\link{ddbs_options}}):
\itemize{
\item \code{duckspatial} (default): A \code{duckspatial_df} (lazy spatial data frame) backed by dbplyr/DuckDB.
\item \code{sf}: An eagerly collected object in R memory, that will return the same data type as the
\code{sf} equivalent (e.g. \code{sf} or \code{units} vector).
}
When \code{name} is provided, the result is also written as a table or view in DuckDB and the function returns \code{TRUE} (invisibly).
}
\description{
Resizes geometries by specified X and Y scale factors. By default, scaling is
performed relative to the centroid of all geometries; if \code{by_feature = TRUE},
each geometry is scaled relative to its own centroid.
}
\examples{
\dontrun{
## load packages
library(duckspatial)
library(dplyr)

# create a duckdb database in memory (with spatial extension)
conn <- ddbs_create_conn(dbdir = "memory")

## read data
countries_ddbs <- ddbs_open_dataset(
  system.file("spatial/countries.geojson", 
  package = "duckspatial")
) |>
  filter(CNTR_ID \%in\% c("PT", "ES", "FR", "IT"))

## store in duckdb
ddbs_write_table(conn, countries_ddbs, "countries")

## scale to 150\% in both directions
ddbs_scale(conn = conn, "countries", x_scale = 1.5, y_scale = 1.5)

## scale to 200\% horizontally, 50\% vertically
ddbs_scale(conn = conn, "countries", x_scale = 2, y_scale = 0.5)

## scale all features together (default)
ddbs_scale(countries_ddbs, x_scale = 1.5, y_scale = 1.5, by_feature = FALSE)

## scale each feature independently
ddbs_scale(countries_ddbs, x_scale = 1.5, y_scale = 1.5, by_feature = TRUE)

}
}
