otra prueba

rm(list=ls())
library(ggplot2)

x<- c(
  seq(-2.1,-1.1,length.out=200), 
  rep(-2.1,200),
  seq(-2.1,-1.2,length.out=200),
  seq(-1.1,-1.5,length.out=200),
  rep(1,200),
  rep(-1.1,200),
  seq(-1.1,-1.2,length.out=200),
  rep(1,200),
  seq(1,2,length.out=200),
  seq(1,2,length.out=200),
  rep(2,200),
  seq(1,2,length.out=200))


y<- c(
  rep(1,200),
  seq(-1,1,length.out=200),
  rep(-1,200),
  rep(0,200),
  seq(0,0,length.out=200),
  seq(-1,0,length.out=200),
  rep(-1,200),
  seq(1,0,length.out=200),
  rep(1,200),
  rep(0,200),
  seq(0,-1,length.out=200),
  rep(-1,200))


z <- rbind(x,y)
steps <- 25
wait_t <- 0

plot(y~x, xlim=c(-2,2), ylim=c(-2,2), asp=1)

Basic Transformations. We will apply matrix transformations to our “GS” matrix defined earlier. The transformation we will do will be

Shear Rotation Enlarge Shrink Projection

# Shear
max_shear <- 2
f <- max_shear/steps 

x11()

for (i in 0:steps) {
  t <- i * f
  S <- matrix(c(1,t,0,1),nrow=2, ncol=2, byrow = TRUE)
  Transx_Sheared = S %*% z
  X <- Transx_Sheared[1,]
  Y <- Transx_Sheared[2,]
  plot(Y~X, xlim=c(-3,3), ylim=c(-3,3), asp=1)
  Sys.sleep(wait_t)
}

max_rotation <- 180  #degrees
f <- max_rotation/steps 

x11()

for (i in 0:steps) {
  t <- i * f
  R <- matrix(c(cos(t * pi / 180),-sin(t * pi / 180),sin(t * pi / 180),cos(t * pi / 180)),nrow=2, ncol=2, byrow = TRUE)
  Transx_Rotated <- R %*% z
  X <- Transx_Rotated[1,]
  Y <- Transx_Rotated[2,]
  plot(Y~X, xlim=c(-3,3), ylim=c(-3,3), asp=1)
  Sys.sleep(wait_t)
}