resize_matrix: Resize Matrix

In tylermorganwall/rayshader: Create Maps and Visualize Data in 2D and 3D

Resize Matrix

Description

Resizes a matrix (preserving contents) by specifying the desired output dimensions or a scaling factor.

Usage

resize_matrix(
  heightmap,
  scale = 1,
  width = NULL,
  height = NULL,
  method = "bilinear"
)

Arguments

heightmap	The elevation matrix.
scale	Default '0.5'. The amount to scale down the matrix. Scales using bilinear interpolation.
width	Default 'NULL'. Alternative to 'scale' argument. The desired output width. If 'width' is less than 1, it will be interpreted as a scaling factor– e.g. 0.5 would halve the resolution for the width.
height	Default 'NULL'. Alternative to 'scale' argument. The desired output width. If 'height' is less than 1, it will be interpreted as a scaling factor– e.g. 0.5 would halve the resolution for the height.
method	Default 'bilinear'. Method of interpolation. Alteratively 'cubic', which is slightly smoother, although current implementation slightly scales the image.

Examples

#Reduce the size of the monterey bay dataset by half

if(run_documentation()) {
montbaysmall = resize_matrix(montereybay, scale=0.5)
montbaysmall %>%
 sphere_shade() %>%
 plot_map()
}
if(run_documentation()) {
#Reduce the size of the monterey bay dataset from 540x540 to 100x100
montbaysmall = resize_matrix(montereybay, width = 100, height = 100)
montbaysmall %>%
 sphere_shade() %>%
 plot_map()
}
if(run_documentation()) {
#Increase the size of the volcano dataset 3x
volcanobig = resize_matrix(volcano, scale=3)
volcanobig %>% 
 sphere_shade() %>%
 plot_map()
}
if(run_documentation()) {
#Increase the size of the volcano dataset 2x, using cubic interpolation
volcanobig = resize_matrix(volcano, scale=3, method="cubic")
volcanobig %>% 
 sphere_shade() %>%
 plot_map()
}

tylermorganwall/rayshader documentation built on Dec. 21, 2024, 4:29 p.m.