我在 x、y、z 中有一个数据文件,并想使用该数据绘制一个 3D 圆锥。我试过 splot 但它只给出最后一个点圆。我的数据文件格式如下:
X y z
0 18 18
10 59 59
20 80 80
任何帮助表示赞赏。
在此先感谢-Abhi
我在 x、y、z 中有一个数据文件,并想使用该数据绘制一个 3D 圆锥。我试过 splot 但它只给出最后一个点圆。我的数据文件格式如下:
X y z
0 18 18
10 59 59
20 80 80
任何帮助表示赞赏。
在此先感谢-Abhi
在这一点上,我认为展示一个简单的脚本可能更容易,该脚本可用于生成 gnuplot 可用于绘制圆锥的格式的数据:
我将使用 python 有两个原因。首先,我非常了解它,其次,它读起来很像伪代码,所以即使你不了解 python,也应该很清楚发生了什么。
import math
h = 2
points_u = map(float,range(-h,h+1)) #[-2.,-1.,0.,1.,2.]
NTHETA = 12 #number of points in theta for the cone
dtheta = 2.*math.pi/NTHETA
points_theta = [dtheta*i for i in range(NTHETA+1)] #list of points in theta
with open('data.txt','w') as fout: #open an output file for the data
for theta in points_theta:
for u in points_u:
#This is how to plot a cone parametrically
#Here I unravel the cone into it's x-y-z components
#The important part is that within the inner loop,
#we're writing data along a single theta. In other words,
#within the inner loop, we write a single straight line which
#is on the surface of the cone.
x = (h-u)/h*math.cos(theta)
y = (h-u)/h*math.sin(theta)
z = u
fout.write('%f %f %f\n'%(x,y,z))
#After the inner loop, you need to insert a blank line to let gnuplot know
#that the particular "scan" is over and it is supposed to start a new "scan"
#After all is said and done, gnuplot will connect the points.
fout.write('\n')
现在这会生成一个数据文件data.txt
。要在 gnuplot 中绘制此数据文件,您可以简单地执行以下操作:
set surface
#set hidden3d #This makes the object "non-transparent"
splot 'data.txt' using 1:2:3 with lines