7.3. ComponentValue and TensorValues with independent values

Until now, the second list of the FoldedRules contained only trivial replacement rules such as → . It is very simple to specify values for the LHS, we just have to call ComponentValue with two arguments:

In[345]:=

Out[345]=

In[346]:=

Out[346]=

Notice what happens if we specify a dependent component

In[347]:=

Out[347]=

First the dependent rule is added and then the value (with a possible sign) is assigned to the corresponding independent component:

In[348]:=

Out[348]=

ComponentValue does not allow the user to introduce an inconsistent value

In[349]:=

Out[349]=

We switch the rule generation messages off

In[350]:=

ComponentValue is threaded on pairs of lists when it has two arguments. This allows us to generate all independent rules with just one command.

In[351]:=

Out[351]=

In[352]:=

Out[352]=

In[353]:=

Out[353]=

Created by Mathematica (May 16, 2008) |