It appears that there are some differences between the implementation of Mathematica on the Unix and Mac platforms and that on the computer lab PC's. This might be due to an insufficiently flexible configuration on set up of the software or possibly due (probably partly ) to the restrictions of the Windows operating system on the PC. These problems seem to affect both the Windows 3.1 and Windows 95 implementations.
For example, to load a package (which extends the default functionality)
successfully on a
Mac or Unix platform it is sufficient to invoke the << command. Under
Unix (SparcSystem 600 workstation):
3 :leonard> math
Mathematica 2.2 for SPARC
Copyright 1988-94 Wolfram Research, Inc.
-- Open Look graphics initialized --
In[1]:= <<Calculus`VectorAnalysis`
In[2]:= v1 = {1,2,3}
Out[2]= {1, 2, 3}
In[3]:= ScalarTripleProduct[v1, v1, v1]
Out[3]= 0
In[4]:= $Packages
Out[4]= {Calculus`VectorAnalysis`, Global`, System`}
In[5]:= Exit
4 :leonard>
and on the Macintosh:
In[1]:= $Packages
Out[1]= {Global`, System`}
In[2]:= <<Calculus`VectorAnalysis`
In[3]:= v1 = {1,2,3}
Out[3]= {1, 2, 3}
In[4]:= ScalarTripleProduct[v1, v1, v1]
Out[4]= 0
In[5]:= $Packages
Out[5]= {Calculus`VectorAnalysis`, Global`, System`}
For the Mac at least, one can use a variety of approaches to cause a
package (e.g. VectorAnalysis) to load e.g.:
Needs["Calculus`VectorAnalysis`"] <<Calculus`VectorAnalysis` <<:Calculus:LaplaceTransform.m
However on the IBM PC lab machines it appears necessary to adopt a more primitive approach and explicitly refer to the file directory structure relative to the current working directory. For example, on a given PC:
In[1]:= $Path
Out[1]= {., C:\WNMATH22\, C:\WNMATH22\PACKAGES\, C:\WNMATH22\PACKAGES\PRELOAD\}
In[2]:= <<CALCULUS\vectoran.m
In[3]:= $Packages
Out[3]= {Calculus`VectorAnalysis`, Global`, System`}
In[4]:= v1 = {1,2,3}
Out[4]= {1, 2, 3}
In[5]:= ScalarTripleProduct[v1, v1, v1]
Out[5]= 0
In[ 6]:= Directory[]
Out[6]= C:\WNMATH22
Unless there is some way to activate the easier mechanisms, it appears that in order to load packages, we need to resort to referring to package files by their actual file names. For example:
<<CALCULUS\vectoran.m for package called VectorAnalysis <<CALCULUS\laplacet.m for package called LaplaceTransform <<integrat.m for package called Integration
Look at the PACKAGES directory for details.