Welcome
Developing
Developing EGL applications
Enterprise Generation Language (EGL) is a programming language that you can use to focus on business problems instead of software technologies. Within the Rational® development environment, you can use EGL wizards and other tools to write complex applications with minimal effort.
EGL Language Reference
The EGL Language Reference covers the fundamental use of the language, including its concepts, syntax, and keywords. This volume is intended for a developer writing EGL applications with some experience in procedural programming.
EGL core system libraries and variables
EGL library mathLib
The EGL mathLib functions perform common mathematical and trigonometric functions.
tan()

Overview
Getting started
Installing
Upgrading and migrating
Developing
- Model driven development of EGL code
- Generating source code from UML models
  You can use transformations to create source code from a UML model. First you must create a transformation parameters file and then apply those parameters to a model.
- Generating the EGL Dependency Graph from EGL projects
- Generating Source Code from OpenAPI Documents
- Developing EGL applications
  Enterprise Generation Language (EGL) is a programming language that you can use to focus on business problems instead of software technologies. Within the Rational® development environment, you can use EGL wizards and other tools to write complex applications with minimal effort.
  - How to use this documentation
  - Additional information about EGL
    The most recent EGL documentation is in the Rational® Business Developer Information Center.
  - EGL Programmer's Guide
    The EGL Programmer's Guide covers using EGL within the Eclipse Integrated Development Environment (IDE), as well as some of the common programming tasks that EGL developers perform.
  - EGL Generation Guide
    The EGL Generation Guide covers the process of converting EGL code to Java™ or COBOL source code, including the processes and the files involved. This section is intended for a developer who will generate or deploy EGL applications.
  - EGL Language Reference
    The EGL Language Reference covers the fundamental use of the language, including its concepts, syntax, and keywords. This volume is intended for a developer writing EGL applications with some experience in procedural programming.
    - General syntax
    - System data parts
    - User-defined data parts
    - Logic parts
    - Correspondence between a JSON string and an EGL variable
      This topic describes the EGL record that corresponds to a JavaScript™ Object Notation (JSON) string. Other topics describe the functions (serviceLib.convertFromJSON() and serviceLib.convertToJSON()) that are used by a Rich UI developer to convert JSON data to or from a variable, as may be necessary to access a third-party REST service. A failure in either function causes a RuntimeException.
    - Correspondence between a JSON string and an EGL variable for zOS and IBM i
      This topic describes the EGL record that corresponds to a JavaScript Object Notation (JSON) string. This topic describes the functions—serviceLib.convertFromJSON() and serviceLib.convertToJSON()—that are used by an EGL developer to convert JSON data to or from a variable either for zOS or IBM i systems. A failure in either function causes a RuntimeException.
    - Special considerations for JSON support on IBM i:
    - Correspondence between an XML string and an EGL variable
      This topic describes the EGL record that corresponds to an Extensible Markup Language (XML) string. Other topics describe the functions (serviceLib.convertFromXML and serviceLib.convertToXML) that are used by a Rich UI developer to convert XML data to or from a variable, as may be necessary to access a third-party REST service.
    - EGL statements
    - EGL core system libraries and variables
      - EGL library dateTimeLib
        The date and time system functions and variables let you manipulate and retrieve the system date and time in a variety of formats.
      - EGL library JavaLib
        The javaLib library access local Java® objects and classes through your generated Java™ code.
      - EGL library lobLib
        The lobLib system library provides support functions for large objects (BLOB and CLOB types).
      - EGL library mathLib
        The EGL mathLib functions perform common mathematical and trigonometric functions.
        abs()
        acos()
        asin()
        assign()
        The mathLib.assign() system function assigns the value of a source expression to a target variable, preserving the rounding behavior that was automatic in EGL version 6.
        atan()
        atan2()
        ceiling()
        cos()
        cosh()
        decimals()
        exp()
        floor()
        frexp()
        ldexp()
        log()
        log10()
        max()
        The mathLib.max() system function returns the greater of two numbers (or numeric expressions).
        min()
        The mathLib.min() system function returns the lesser of two numbers (or numeric expressions).
        modf()
        pow()
        The mathLib.pow() system function returns a number raised to the power of a second number.
        precision()
        The mathLib.precision() system function returns the precision for a variable.
        round()
        The mathLib.round() system function rounds the value of an expression to a specified power of ten (for example, to the nearest thousands) and returns the result.
        sin()
        The mathLib.sin() system function returns the sine of a number whose value represents an angle that is expressed in radians.
        sinh()
        The mathLib.sinh() system function returns the hyperbolic sine of a number whose value represents an angle that is expressed in radians.
        sqrt()
        stringAsDecimal()
        stringAsFloat()
        stringAsInt()
        tan()
        tanh()
      - EGL library serviceLib
        The serviceLib functions get and set service variable information.
      - EGL library strLib
        The strLib functions manipulate and convert data to and from STRING variables and format date/time variables.
      - EGL library sysLib
        The sysLib system library contains miscellaneous functions and one variable.
      - sysVar system variable
        The sysVar system variable holds a variety of values.
      - EGL library XMLLib
        This topic describes the XMLLib functions and variable definitions.
    - Accessing data in EGL
      Whenever you access a data store in EGL, the data goes into a record.
    - Applications with user interfaces
    - VisualAge® Generator compatibility
    - Appendices
    - Importing product-supplied projects
      You can click a link to download the current version of Rich UI projects. The capability is useful if you deleted a project or want a clean version.
  - Rational® COBOL Runtime Guide for zSeries®
    This manual provides information about customizing and administering the IBM® Rational® COBOL Runtime.
  - Rational® Business Developer EGL Server Guide for IBM® i
    This manual provides information about customizing and administering EGL Server for IBM® i on the host.
  - Generation for VSE Feature Reference
    This reference manual provides z/VSE-specific information about developing and generating EGL programs in the VSE environment.
- Source code analysis with code review
  With code review, you can create configurations of coding rules for EGL source code. You can then run the configurations to check the source code for consistency with the rules.
- Responsive Design Support in RBD
  What is Responsive Design? Responsive design is an approach for creation of web pages that automatically scales its content and elements to match the screen size on which it is viewed. So, instead of designing multiple websites for different devices with variable screen sizes, we can design just one website that scales up or down automatically, to match the device it’s being viewed on.
Samples
Troubleshooting and support
EGL runtime error messages
Reference
Glossary
Using the help
Notices for IBM Rational Business Developer documentation

tan()

The mathLib.tan() system function returns the tangent of a number whose value represents an angle expressed in radians.

Syntax

  mathLib.tan(numericField FLOAT in)
  returns (result FLOAT)

numericVariable: Input can be any variable or expression that is assignment compatible with the FLOAT type (see "Assignment compatibility in EGL"). The value represents an angle in radians.
result: A FLOAT value.

Example

  result = mathLib.tan(myVar);