Controlling Numerical Evaluation

Attributes for controlling numerical evaluation.

Usually (RefLink[N, paclet:ref/N]) goes inside functions and gets applied to each of their arguments:

N[f[2/3,Pi]]

This tells the Wolfram Language not to apply (RefLink[N, paclet:ref/N]) to the first argument of f:

SetAttributes[f,NHoldFirst]

Now the first argument of f is left in its exact form:

N[f[2/3,Pi]]