SVD动态图

library(gganimate)

library(gifski)

# 构造数据

phi<-pi/6

theta<-pi/3

c<-matrix(c(cos(phi),sin(phi),-sin(phi),cos(phi)),

          nrow=2,byrow=TRUE)

b<-matrix(c(5,0,0,1),nrow=2,byrow=TRUE)

a<-matrix(c(cos(theta),-sin(theta),sin(theta),cos(theta)),

          nrow=2,byrow=TRUE)

A<-a%*%b%*%c

A

x<-matrix(c(1,0,0,1),nrow=2,byrow=TRUE)

rotate1<-c%*%x

stretch<-b%*%c%*%x

rotate2<-a%*%b%*%c%*%x

svd_trans<-cbind(x,rotate1,stretch,rotate2)

df1<-data.frame(t=c(1,1,2,2,3,3,4,4),

                x1=c(0,0,0,0,0,0,0,0),

                y1=c(0,0,0,0,0,0,0,0),

                x2=svd_trans[1,],

                y2=svd_trans[2,],

                point=c('A','B','A','B','A','B','A','B'))

Points<-matrix(c(cos(seq(0,2*pi,0.01*pi)),

                 sin(seq(0,2*pi,0.01*pi))),

               byrow=TRUE,nrow=2)

Points_rotate1<-c%*%Points

Points_stretch<-b%*%c%*%Points

Points_rotate2<-a%*%b%*%c%*%Points

Points_svd<-cbind(Points,Points_rotate1,Points_stretch,Points_rotate2)

df2<-data.frame(Points_x=Points_svd[1,],

                Points_y=Points_svd[2,],

                t=rep(c(1,2,3,4),each=ncol(Points)))

# 绘制图形

p<-ggplot()+

  geom_segment(data=df1,aes(x=x1,y=y1,xend=x2,yend=y2,color=point),

               arrow=arrow(length = unit(0.03, "npc")))+

  geom_point(data=df2,aes(x=Points_x,y=Points_y),size=0.01)+

  labs(x=expression(x),y=expression(y))+

  theme(legend.position="none")+

  transition_states(t)

animate(p, renderer = gifski_renderer())
巴特西

SVD动态图

最新文章

热门文章
