FME Transformers: 2024.2
Generates a uniformly distributed random number.
The random number is x, where Minimum Value <= x <= Maximum Value.
Usage Notes
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RandomNumberGenerator generates random numbers using the Tcl rand() function. The numbers generated by this function may not be considered truly random, because rand() requires an initial seed value, which determines the sequence of numbers that is generated. There are no more than 2^31 possible random number sequences, and these sequences repeat after 2^31 times. The same seed value, used repeatedly, generates the same numbers. Additionally, the sequence, by design, never produces the same number twice in a row.
Configuration
Output Ports
Note Feature order may change in relation to other output ports. Feature order per port is maintained.
<Rejected> (Dynamic)
The dynamic <Rejected> port appears when a parameter is set to a non-literal value that might make processing impossible.
For example, if a numeric parameter such as Line Width, Count Start, or Decimal Places is set to an expression, attribute value, or user parameter, it is possible to pass in a non-numeric value that cannot be used. Decimal Places = Cat cannot be processed, so the feature will be output via this port.
Rejected features will have an fme_rejection_code attribute explaining the reason for rejection.
Rejected Feature Handling: can be set to either terminate the translation or continue running when it encounters a rejected feature. This setting is available both as a default FME option and as a workspace parameter.
Parameters
General
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Minimum Value |
Specify the minimum value that can be generated. |
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Maximum Value |
Specify the maximum value that can be generated. |
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Decimal Places |
The random number will be rounded to the number of digits specified in the Decimal Places parameter. Note that in general, when the Minimum Value and Maximum Value is specified in an exponential form (for example, "1.0e+25"), Decimal Places refers to the number of decimal places in the exponential form. If Minimum Value or Maximum Value have more decimal places than the Decimal Places requested for the result, the actual minimum value used will be rounded up and the actual maximum value used will be rounded down to the requested decimal places. This is to ensure that the generated random number will always fall between the Minimum Value and the Maximum Value. |
Output Attribute Name
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Generated Number |
Name the attribute to contain the generated number. |
Editing Transformer Parameters
Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click 
beside the applicable parameter.
How to Set Parameter Values
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters.
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
Content Types
| These functions manipulate and format strings. | |
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Special Characters |
A set of control characters is available in the Text Editor. |
| Math functions are available in both editors. | |
| Date/Time Functions | Date and time functions are available in the Text Editor. |
| These operators are available in the Arithmetic Editor. | |
| These return primarily feature-specific values. | |
| FME and workspace-specific parameters may be used. | |
| Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
Table Tools
Transformers with table-style parameters have additional tools for populating and manipulating values.
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Row Reordering
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Enabled once you have clicked on a row item. Choices include:
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Cut, Copy, and Paste
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Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. |
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Filter
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Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output. |
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Import
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Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. |
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Reset/Refresh
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Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. |
Note: Not all tools are available in all transformers.
For more information, see Transformer Parameter Menu Options.
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