HW 1

library(animation)

x=c(rep(0,500),seq(0,1,length.out=1000), rep(1,500))
y=c(seq(-1,1,length.out=500),rep(0,1000), seq(-1,1,length.out=500))
z=rbind(x,y)
plot(y~x, xlim=c(-3,3), ylim=c(-3,3))

dev.control('enable')

myani=ani.record(reset=TRUE, replay.cur=FALSE)

a=diag(2)
x11()
for (i in seq(-3,3,length.out=100)) {
  a[1,1]=i
  newmat=apply(z,2,function(x) a%*%x)
  plot(newmat[2,]~newmat[1,], xlim=c(-3,3), ylim=c(-3,3))
  ani.record()
  #Sys.sleep(1)
}

a=diag(2)
for (i in seq(-3,3,length.out=100)) {
  a[1,2] = i
  newmat=apply(z,2,function(x) a%*%x)
  plot(newmat[2,]~newmat[1,], xlim=c(-3,3), ylim=c(-3,3))
  ani.record()
}

a=diag(2)
for (i in seq(-3,3,length.out=100)) {
  a[2,2] = i
  newmat=apply(z,2,function(x) a%*%x)
  plot(newmat[2,]~newmat[1,], xlim=c(-3,3), ylim=c(-3,3))
  ani.record()
}

myf=function(x) {matrix(c(cos(x), -sin(x), sin(x), cos(x)), byrow=TRUE,nrow=2)}

for (i in seq(0,20,length.out=100)) {
  a=myf(i)
  newmat=apply(z,2,function(x) a%*%x)
  plot(newmat[2,]~newmat[1,], xlim=c(-3,3), ylim=c(-3,3))
  ani.record()
}

#saveGIF(ani.replay(), img.name='tmp', convert='magick',clean=TRUE)