Mathematica 9 is now available
THIS IS DOCUMENTATION FOR AN OBSOLETE PRODUCT.
SEE THE DOCUMENTATION CENTER FOR THE LATEST INFORMATION.
Mathematica > Numerical Evaluation & Precision >

N

N[expr]
gives the numerical value of expr.
N[expr, n]
attempts to give a result with n-digit precision.
  • Unless numbers in expr are exact, or of sufficiently high precision, N[expr, n] may not be able to give results with n-digit precision.
  • N[expr, n] may internally do computations to more than n digits of precision.
  • $MaxExtraPrecision specifies the maximum number of extra digits of precision that will ever be used internally.
  • The precision n is given in decimal digits; it need not be an integer.
  • N[0] gives the number 0. with machine precision.
  • N converts each successive argument of any function it encounters to numerical form, unless the head of the function has an attribute such as NHoldAll.
  • You can define numerical values of functions using N[f[args]]:=value and N[f[args], n]:=value.
  • N[expr, {p, a}] attempts to generate a result with precision at most p and accuracy at most a.
  • N[expr, {Infinity, a}] attempts to generate a result with accuracy a.
  • N[expr, {Infinity, 1}] attempts to find a numerical approximation to the integer part of expr.
New in 1 | Last modified in 5
© 2013 Wolfram Research, Inc. Japanese
Ask a question about this page  |  Suggest an improvement  |  Leave a message for the team