使用 python 在 output 中没有绘制图表

Question

I have a code and I want to see output using vpython. following is the code

#!/usr/local/bin/ python3
from vpython import *
Plot1 = gcurve ( color = color . white )
for x in arange(0., 8.1, 0.1):
        Plot1.plot( pos = (x, 5.*cos(2.*x)*exp(-0.4*x)) )

graph1 = gdisplay ( width =600, height =450 ,\
        title="Visual 2D Plot", xtitle="x", ytitle="f(x)",\
        foreground = color . black , background = color . white )
Plot2 = gdots ( color = color . black )

for x in arange( -5., +5, 0.1 ):
        Plot2.plot(pos = (x, cos(x)))

it is giving this error, however, it is showing a box of a white background with no plot in it. Error: name 'gdisplay' is not defined

how can I define g display?

Answer 1

You need to import the visual module of VPython:

from visual.graph import *

Answer 2

With VPython 7 the name is "graph", not gdisplay. And "from vpython import *" includes the graph object.