Random number generator

• The default value for the seed is zero.
• If a tool using the random values (for example, CreateRandomRaster, CreateRandomPoints, or CalculateValue) is run twice with the same seed, the output will be identical. Control over the seed allows you to reproduce your results.
• If a random number generator is defined globally, one stream of random values will be created. Each subsequent tool or tools within a ModelBuilder model will pull the next available value from the stream as needed.
• Multiple random number generator streams can be used in a ModelBuilder model by creating them locally for the desired tools that use random numbers. Each tool can have its own stream from which to pull random values as needed. Only the tool with the local stream can pull values from that stream. There is no limit to the number of local streams.
• The STANDARD_C random number generator is the same random number generator accompanying the standard C libraries from Microsoft. The source code is contained in a file called RAND.c and the file is generally stored in ProgramFiles/Microsoft Visual Studio/VC98/CRT/SRC.
• Learn more about specifying general settings
• Learn more about environment settings
• Learn more about environment levels and hierarchy

Command line example

randomGenerator "4 MERSENNE_TWISTER"

Script example

import arcgisscripting
gp = arcgisscripting.create()

gp.workspace = "h:/workspace"
gp.RandomGenerator = "4 MERSENNE_TWISTER"