ggplot2练习

图源于电力电子课本65页——电容滤波的单相不可控整流电路。

f<-function(w,d)
{
  l<-w/sqrt(w^2+1)*exp(-atan(w)/w)*exp(-d/w)
  r<-sin(d)
  return(l-r)
}
w<-seq(0.01,60,0.01)
d<-rep(0,length(w))
s<-rep(0,length(w))
for(i in 1:length(w))
{
  root<-uniroot(f,c(0,pi/2),w=w[i],tol=0.01)
  d[i]<-root$root
  s[i]<-pi-d[i]-atan(w[i])
}

library(ggplot2)
DataSet1<-data.frame(w,value=d,lab=rep("d",length(w)))
DataSet2<-data.frame(w,value=s,lab=rep("s",length(w)))
DataSet <- rbind(DataSet1,DataSet2)

p<-ggplot(data=DataSet,aes(w,value,color=lab))
p+geom_line()+
  scale_colour_hue("value",breaks=c("d","s"),labels=c(expression(delta),expression(theta)))+
  labs(x=(expression(omega*RC/rad)),y=expression(list(delta,theta)/rad))+
  xlim(0,60)+ylim(0,pi)+
  scale_x_continuous(expand = c(0,0))+
  scale_y_continuous(breaks=round(c(0,pi/6,pi/3,pi/2,2*pi/3,5*pi/6,pi),digits=2),
                     labels=expression(0,pi/6,pi/3,pi/2,2*pi/3,5*pi/6,pi),expand = c(0, 0))

练习了：

1. 自定义离散色彩标度；
2. 修改坐标轴标签；
3. 修改坐标范围；
4. 修改显示刻度；
5. expression数学表达式。

更新补充：图源于电力电子课本143页——单相交流调压电路。

AngleToRadian<-function(alpha)
{
  return(alpha*pi/180)
}
RadianToAngle<-function(alpha)
{
  return(alpha/pi*180)
}
f<-function(alpha,theta,varphi)
{
  var1<-sin(alpha+theta-varphi)
  if(varphi==0)
    var2<-0
  else
    var2<-sin(alpha-varphi)*exp(-theta/tan(varphi))
  return(var1-var2)
}
alpha<-seq(0,180-2,0.5)
varphi<-seq(0,90,15)
data<-data.frame()

for(a in alpha)
{
  for(v in varphi)
  {
    if(v<=a){
    t=uniroot(f,c(1e-3,pi+1e-3),alpha=AngleToRadian(a),
              varphi=AngleToRadian(v),tol=0.001)
    result<-c(a,RadianToAngle(t$root),v)
    data<-rbind(data,result)}
  }
}
names(data)<-c("alpha","theta","varphi")

data$I_VTN<-rep(0,dim(data)[1])
for(i in 1:dim(data)[1])
{
  a<-AngleToRadian(data$alpha[i])
  t<-AngleToRadian(data$theta[i])
  if(data$varphi[i]==90)
    v<-AngleToRadian(data$varphi[i]-1)
  else
    v<-AngleToRadian(data$varphi[i])

  data$I_VTN[i]<-1/(2*sqrt(pi))*sqrt(t-sin(t)*cos(2*a+v+t)/cos(v))
}
library(ggplot2)
theme_set(theme_light())
ggplot(data=data,aes(alpha,theta,color=factor(varphi)))+
  geom_line()+scale_colour_hue(expression(varphi/(degree)))+
  labs(x=(expression(alpha/(degree))),y=expression(theta/(degree)))
ggplot(data=data,aes(alpha,I_VTN,color=factor(varphi)))+geom_line()+
  geom_line()+scale_colour_hue(expression(varphi/(degree)))+
  labs(x=(expression(alpha/(degree))),y=expression(I[VTN]))