vi.grid.illusion {animation}R Documentation

Visual Illusions: Scintillating grid illusion and Hermann grid illusion

Description

A grid illusion is any kind of grid that deceives a person's vision. The two most common types of grid illusions are Hermann grid illusions and Scintillating grid illusions. This function provides illustrations for both illusions.

Usage

vi.grid.illusion(nrow = 8, ncol = 8, lwd = 8, cex = 3, 
    col = "darkgray", type = c("s", "h"))

Arguments

nrow number of rows for the grid
ncol number of columns for the grid
lwd line width for grid lines
cex magnification for points in Scintillating grid illusions
col color for grid lines
type type of illusions: 's' for Scintillating grid illusions and 'h' for Hermann grid illusions

Details

This is actually a static image; pay attention to the intersections of the grid and there seems to be some moving points (non-existent in fact).

Value

None.

Note

In fact there isn't any animation!

Author(s)

Yihui Xie

References

http://en.wikipedia.org/wiki/Grid_illusion

http://animation.yihui.name/animation:misc#visual_illusions

See Also

points, abline

Examples

# default to be Scintillating grid illusions 
vi.grid.illusion()

# set wider lines to see Hermann grid illusions 
vi.grid.illusion(type = "h", lwd = 22, nrow = 5, ncol = 5, 
    col = "white") 

[Package animation version 1.0-1 Index]