Random Number Generation

This article was previously published under Q86523
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SUMMARY
In Microsoft Excel, the RAND function uses the following iterativemethod to calculate pseudo-random numbers:

The first random number:

   random_number=fractional part of (9821 * r + 0.211327),   where r = .5				


Successive random numbers:

   random_number=fractional part of (9821 * r + 0.211327),   where r = the previous random number				


This formula will provide up to 1 million different numbers.
MORE INFORMATION
Computers cannot generate truly random numbers. Instead, they return aseries of numbers based on a mathematical relationship that simulates"randomness." The "randomness" exhibited by the numbers is a functionof the mathematical formula used by the random number generator.

In Microsoft Excel for Windows, adding randomize=1 to the [Microsoft Excel]section of the appropriate .INI file for your version of Microsoft Excelwill cause "r" to be determined from the system clock (which adds a furtherdegree of randomness to the numbers generated).

   For this version         The name of your   of Microsoft Excel       .INI file is this   -----------------------------------------   5.0                      EXCEL5.INI   4.0                      EXCEL4.INI   3.0                      EXCEL.INI				


Note that there is no such setting with Microsoft Excel for OS/2 orMicrosoft Excel for the Macintosh.

NOTE: Excel 5.0 defaults to the RANDOMIZE=1 setting. Previous versions ofMicrosoft Excel defaulted to RANDOMIZE=0.
1.0 1.00 1.03 1.04 1.06 1.5 1.50 2.0 2.00 2.01 2.1 2.10 2.2 2.20 2.21 3.0 3.00 4.0 4.00 rand random algorithm Excel
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Article ID: 86523 - Last Review: 12/04/2015 09:15:53 - Revision: 1.4

Microsoft Excel 97 Standard Edition, Microsoft Excel 95 Standard Edition, Microsoft Excel 5.0 Standard Edition, Microsoft Excel 98 for Macintosh

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