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3.1.9 Advanced Topic: Controlling Numerical Evaluation

Attributes for controlling numerical evaluation.

  • Usually N goes inside functions and gets applied to each of their arguments.
  • In[1]:= N[f[2/3, Pi]]


  • This tells Mathematica not to apply N to the first argument of f.
  • In[2]:= SetAttributes[f, NHoldFirst]

  • Now the first argument of f is left in its exact form.
  • In[3]:= N[f[2/3, Pi]]