Re: Writing Lists to files

*To*: mathgroup at yoda.physics.unc.edu*Subject*: Re: Writing Lists to files*From*: twj (Tom Wickham-Jones)*Date*: Sun, 13 Mar 1994 09:43:21 -0600

Robert Love writes >How do I write a graphics object to a file and later read it back in? .. >I now have a function to process the raw data, make Graphics3D lists >and write it to a file, and a function to read it back in and render >it. It works only as long as I have the same MMA session going. If >I come back another day, I can't just use the file produced by the >write function. I have to execute it in this session and then read >it. The error when I try to show what I've read in is "Symbol is a >type of graphics". Yet if I look at the file that was written it >looks like: >{Graphics3D[Line[{{-0.1074786999302791, 0.0001500686726859751, > > -0.994207376024082}, {-0.0987432588630104, >-0.003310157494793516, Without seeing the EXACT input it is difficult to comment on why this is not working. However it is possible to make a Graphics3D object and save it in a file to be restored later. The same can be done for any other Mathematica expression. coringa [40] twj> math Mathematica 2.2 for NeXT Copyright 1988-93 Wolfram Research, Inc. -- NeXT graphics initialized -- In[1]:= a = ParametricPlot3D[ {Sin[t], Cos[t], z}, {t,0,2Pi}, {z,0,2}] Out[1]= -Graphics3D- In[2]:= a >> file.dat (* save the object *) In[3]:= Exit In[2] is shorthand for Save[ "file.dat", a] coringa [41] twj> math Using porting image. Mathematica 2.2 for NeXT Copyright 1988-93 Wolfram Research, Inc. -- NeXT graphics initialized -- In[1]:= a = << file.dat (* get the object keep as value of symbol a*) Out[1]= -Graphics3D- In[2]:= Show[ a] Out[2]= -Graphics3D- In[1] is shorthand for a = Get[ "file.dat"] Save will write the definitions of a symbol into a file. Get will input the file and turn the contents into Mathematica expressions. I hope this is useful. Tom Wickham-Jones WRI