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R rgl 3d对数比例图和天线方向图

rgl 3d logging r

Alex P · 技术社区 · 7 年前

首先,在分享我的问题之前,我想分享一些代码,这些代码可能对外面的一些人有所帮助。我一直在寻找一些时间代码来绘制3d天线测量,但我找不到这样的代码。问题是天线测量具有极坐标,典型的3d绘图函数使用笛卡尔坐标。所以我下面的代码就是这么做的(我不是一个高级程序员,所以我相信有人能够优化它的使用)。代码可以直接运行,我添加了注释以使其更易于阅读。

require("rgl")
require("fields")
degreeToRadian<-function(degree){
  return   (0.01745329252*degree)
}

turnPolarToX<-function(Amplitude,Coordinate){
  return (Amplitude*cos(degreeToRadian(Coordinate)))
}

turnPolarToY<-function(Amplitude,Coordinate){
  return (Amplitude*sin(degreeToRadian(Coordinate)))
}


#  inputs for the code
test<-runif(359,min=-50,max=-20) # the 359 elements correspond to the polar coordinates of 1 to 359
test2<-runif(359,min=-50,max=-20)  # the 359 elements correspond to the polar coordinates of 1 to 359
test3<-runif(359,min=-50,max=-20)  # the 359 elements correspond to the polar coordinates of 1 to 359

# My three input vectors above are considered to be dBm values, typically unit for antenna or propagation measurements
# I want to plot those on three different 3d planes the XY, the YZ and the ZX. Since the rgl does not support
# polar coordinates I need to cast my polar coordinates to cartesian ones, using the three functions
# defined at the beginning. I also need to change my dBm values to their linear relative ones that are the mW


# Convert my dBm to linear ones
test<-10^(test/10)
test2<-10^(test2/10)
test3<-10^(test3/10) 

# Start preparing the data to be plotted in cartesian domain
X1<-turnPolarToX(test,1:359)
Y1<-turnPolarToY(test,1:359)
Z1<-rep(0,359)


X2<-turnPolarToX(test2,1:359)
Y2<-rep(0,359)
Z2<-turnPolarToY(test2,1:359) 

X3<-rep(0,359)
Y3<-turnPolarToX(test3,1:359)
Z3<-turnPolarToY(test3,1:359)


# Time for the plotting now

Min<-min(test,test2,test3)
Max<-max(test,test2,test3)

bgplot3d( suppressWarnings ( 
    image.plot( legend.only=TRUE, legend.args=list(text='dBm/100kHz'), zlim=c(Min,Max),col=plotrix::color.scale(seq(Min,Max,length.out=21),c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)))
    ) # zlim is the colorbar numbers
) 

# for below alternatively you can also use the lines3d to get values
points3d(X1,Y1,Z1,col=plotrix::color.scale(test,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)
points3d(X2,Y2,Z2,col=plotrix::color.scale(test2,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)
points3d(X3,Y3,Z3,col=plotrix::color.scale(test3,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)

我现在的问题是,我的绘图理想情况下,我希望在rgl数据包不支持的对数尺度上!如果我尝试在X,Y,Z上使用log来压缩它们,我会得到一个错误,即log没有定义为负数(当然这是正确的)。当不支持对数比例打印时,您认为如何解决压缩轴值的问题?

谢谢你的回复亚历克斯

1 回复 | 直到 7 年前

user2554330 7 年前

将对数比例应用于X、Y和Z没有意义。只需将其应用于原始数据,并将记录的值转换为极坐标。

完成后,可以使用axis3d()函数将带有任意标签的轴添加到绘图中。例如,如果您希望原点对应于-50 dBm,您可以跳过到线性坐标的转换,只需添加50。在计算标签时,您需要撤消此操作。以下是您的示例,已修改:

require("rgl")
require("fields")
degreeToRadian<-function(degree){
  return   (0.01745329252*degree)
}

turnPolarToX<-function(Amplitude,Coordinate){
  return (Amplitude*cos(degreeToRadian(Coordinate)))
}

turnPolarToY<-function(Amplitude,Coordinate){
  return (Amplitude*sin(degreeToRadian(Coordinate)))
}


#  inputs for the code
test<-runif(359,min=-50,max=-20) # the 359 elements correspond to the polar coordinates of 1 to 359
test2<-runif(359,min=-50,max=-20)  # the 359 elements correspond to the polar coordinates of 1 to 359
test3<-runif(359,min=-50,max=-20)  # the 359 elements correspond to the polar coordinates of 1 to 359

# Add an offset of 50 to the values.

test <- test + 50
test2 <- test2 + 50
test3 <- test3 + 50

# Start preparing the data to be plotted in cartesian domain
X1<-turnPolarToX(test,1:359)
Y1<-turnPolarToY(test,1:359)
Z1<-rep(0,359)


X2<-turnPolarToX(test2,1:359)
Y2<-rep(0,359)
Z2<-turnPolarToY(test2,1:359) 

X3<-rep(0,359)
Y3<-turnPolarToX(test3,1:359)
Z3<-turnPolarToY(test3,1:359)


# Time for the plotting now

Min<-min(test,test2,test3)
Max<-max(test,test2,test3)

bgplot3d( suppressWarnings ( 
    image.plot( legend.only=TRUE, legend.args=list(text='dBm/100kHz'), zlim=c(Min,Max)-50,col=plotrix::color.scale(seq(Min-50,Max-50,length.out=21),c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)-50))
    ) # zlim is the colorbar numbers
) 

# for below alternatively you can also use the lines3d to get values
points3d(X1,Y1,Z1,col=plotrix::color.scale(test,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)
points3d(X2,Y2,Z2,col=plotrix::color.scale(test2,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)
points3d(X3,Y3,Z3,col=plotrix::color.scale(test3,c(0,1,1),c(0,1,0),0,xrange=c(Min,Max)),add=TRUE)

# Add axes

labels <- pretty(c(-50, -20))
axis3d("x", at = labels + 50, labels = labels, pos = c(NA, 0, 0) )
axis3d("y", at = labels + 50, labels = labels, pos = c(0, NA, 0) )
axis3d("z", at = labels + 50, labels = labels, pos = c(0, 0, NA) )

在我的系统中,它产生了这样的显示:

您可能需要添加圆,以显示比例如何在每个平面上继续。这段代码可以做到:

theta <- seq(0, 2*pi, len = 100)
for (i in seq_along(labels)) {
  x <- (labels[i] + 50)*cos(theta)
  y <- (labels[i] + 50)*sin(theta)
  lines3d(x, y, 0)
  lines3d(x, 0, y)
  lines3d(0, x, y)
}