Add little arrow tips at the end of the coordinate axes

edit

Could you do something like this?

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| Sage Version 4.7.2, Release Date: 2011-10-29                       |
| Type notebook() for the GUI, and license() for information.        |
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sage: def myAxes(size=1,type='arrow',width=0,color='black'):
....:         if type=='line':
....:             if width==0: width=1
....:         xAxis = line3d([(0,0,0),(size,0,0)],width=width,color=color)
....:         yAxis = line3d([(0,0,0),(0,size,0)],width=width,color=color)
....:         zAxis = line3d([(0,0,0),(0,0,size)],width=width,color=color)
....:     if type=='arrow':
....:             if width==0: width=.5
....:         xAxis = arrow3d((0,0,0),(size,0,0),width=width,color=color)
....:         yAxis = arrow3d((0,0,0),(0,size,0),width=width,color=color)
....:         zAxis = arrow3d((0,0,0),(0,0,size),width=width,color=color)
....:     xAxis += text3d("x", (size*1.1,0,0))
....:     yAxis += text3d("y", (0,size*1.1,0))
....:     zAxis += text3d("z", (0,0,size*1.1))
....:     return(xAxis+yAxis+zAxis)
....: 
sage: myAxes(color='blue').show()
sage: