This is documentation for Mathematica 8, which was
based on an earlier version of the Wolfram Language.
View current documentation (Version 11.1)

Real

Real
is the head used for real (floating-point) numbers.
  • can be used to stand for a real number in a pattern.
  • You can enter a floating-point number of any length.
  • You can enter a number in scientific notation by using the form .
  • You can enter a floating-point number in base b using . The base must be less than 36. The letters - or - are used in sequence to stand for digits 10 through 35.
  • Real is also used to indicate an approximate real number in Read.
Enter a real number:
Real is the Head for real numbers:
Enter a real number:
In[1]:=
Click for copyable input
Out[1]=
Real is the Head for real numbers:
In[2]:=
Click for copyable input
Out[2]=
Real numbers entered with just a few digits are generally represented as machine reals:
Enter a real number with many significant digits:
Arbitrary-precision reals are used when too many digits are given for a machine number:
Its Accuracy is based on the number of digits to the right of the decimal point:
Enter a real number with a specified Precision:
Enter a real number with a specified Accuracy:
Enter a real number with an exponent:
Enter a real number with an exponent and specified precision:
Enter a real number in binary:
Enter a real number in binary with precision specified in terms of bits:
Enter a real number in hexadecimal:
Enter a real number in base 35:
Format a real number using base 2:
can be used to represent a real number in a pattern:
A rule that replaces real numbers with nearby rationals:
Determine if a matrix consists entirely of approximate reals:
A rule that rounds all reals to have two digits after the decimal point:
Divide a restaurant bill to the nearest penny:
Define a function that only works for reals:
Define a function that has a special case for reals:
For integers and rationals use the corresponding approximate real:
Reals are numbers:
Real is used for approximate reals:
Reals are atomic objects with no subexpressions:
Use different formats for displaying a real number:
Use Reals in assumptions and to indicate domain conditions:
Real is only the head for approximate real numbers:
You can use the following function to test for numbers on the real axis:
New in 1 | Last modified in 3