Glossary
- API
- Application Programming Interface. A set of functions that can be called from
an application program to access features of another program.
- Assembly
- The Assembly class is the primary building block of the “system of systems”
aspect of OpenMDAO. Each assembly has one or more Drivers that control
iteration of Components within the Assembly.
An assembly is also a Component, so hierarchies of assemblies can be created.
- AXOD
- Axial-Flow Turbine Off-Design. A a computer code used for
preliminary studies of the gas turbine system.
- branch
- Bazaar term for an ordered series of revisions (see revision
below) that describes the history of a set of files.
- CAD
- Computer-Aided Design. An automated system for the design, drafting, and
display of graphically oriented information.
- CAE
- Computer-Aided Engineering. Using computers to design, analyze, and
manufacture products and processes.
- CAPRI
- Computational Analysis Programming Interface. CAPRI is a CAD vendor-neutral
programming interface that supports direct communication of geometry data between
an application and a CAD system.
- Case
- An object containing a collection of names and values of inputs and/or outputs that
are associated with a given ‘run’ or iteration of a model.
- CaseIterator
- An object that iteratively supplies Case objects. This iterator could be tied
to a simple file, a database, or some object that generates Case objects
dynamically.
- CFD
- Computational Fluid Dynamics. A branch of fluid mechanics that uses numerical
methods and algorithms to solve and analyze problems that involve fluid flows.
- CO
- Collaborative Optimization (CO). See Collaborative Optimization (CO).)
- CommandLineWrapper
- A component that runs a separate executable program via a system call.
- commit
- Bazaar command that records a change. A change is committed to a developer’s local
repository.
- Component
- An object with input and output variables that performs some sort of calculation.
- components
- See Component above.
- CONMIN
- Stands for “CONstraint MINimization.” CONMIN is a gradient descent
optimization algorithm developed by NASA. The simple tutorial in the User
Guide contains information on using CONMIN for an both an unconstrained optimization and a constrained optimization.
- Container
- An object containing variables and possibly other Containers. It’s used as a way to
give structure to groups of input or output variables.
- Coverage
- A Python module that measures code coverage during test execution.
- decorator
- A Python module that aims to simplify the creation of well behaved decorators for the average
programmer. A decorator is well behaved if the wrapped function that it returns has the same
doc string, argument list, and other attributes of the function being wrapped.
- DLL
- Dynamically Loadable Library
- docstring
- A string that describes a module, function, class, or method definition. The docstring is a
special attribute of an object. Docstrings are used to document OpenMDAO code as well as
many packages written Python.
- docutils
- Docutils is a modular system for processing documentation into useful
formats, such as HTML, XML, and LaTeX. For input Docutils supports
reStructuredText, an easy-to-read, what-you-see-is-what-you-get plain text
markup syntax.
- Driver
- A Driver’s function is to iterate over a Workflow until some
condition is met. The simplest Driver executes a Workflow only once.
Other Drivers, such as Optimizers or Parameter Studies, would execute
the Workflow a variable number of times based on their inputs.
- egg
- A zip file with a specified internal directory structure that
contains a Python package or module. It is similar to a jar file in java. For
more information on eggs, see PythonEggs.
- eggs
- See egg above.
- Enum
- A variable type which supports a
list of discrete allowed values. The list of allowed values can be of arbitrary
length, and elements can be of any type.
- F2PY
- Fortran to Python interface generator.
- Factory
- An object that knows how to create objects of specific types.
- FactoryManager
- Multiple Factory derived objects can be registered with
the FactoryManager to allow creation of objects in various ways, e.g., locally
via import and remotely via an ObjServer.
- Fake Finite Difference
- The Fake Finite Difference (FFD) method was developed to support an efficient way to calculate
gradients for mixed models, that is, models that contain both components that can provide
derivatives and components that cannot. When a component has a set of specified derivatives,
they are used to replace the component’s output with the first-order Taylor series expansion
whenever the optimizer initiates a finite difference estimation of the gradient. This is
called Fake Finite Difference.
- FEM
- Finite Element Method. A numerical technique for finding approximate
solutions of partial differential equations (PDE) as well as of integral
equations. A structural analysis method which discretizes a continuum model of a
complex structure to a discrete model of a finite number of degrees of freedom.
- GA
- Genetic algorithm
- Float
- A variable type which represents a floating point number. It
also also allows for the specification of units and specification of
upper and lower bounds.
- Genetic
- OpenMDAO genetic algorithm optimizer based on the Pyevolve genetic algorithm,
which is a complete genetic algorithm framework written in Python. (PyEvolve
was developed and is actively maintained by Christian S. Perone.)
- GUI
- Graphical User Interface. A computer operating system that is based upon icons
and visual relationships rather than text.
- IGeomQueryObject
- An interface to an object having physical dimensions and shape, with
properties that can be queried.
- IDF
- Individual Design Feasible. (See Individual Design Feasible (IDF).)
- Int
- A variable type which represents numbers having integer values.
- IPC
- Interprocess communication
- iteration hierarchy
- A tree structure of Drivers and Components all operating within the same
Assembly. Components are leaf nodes, and the branches coming from each
Driver node are determined by the contents of the Driver’s workflow.
- Jinja
- A small but fast and easy-to-use stand-alone template engine written in pure
Python.
- Jinja2
- Jinja2 is the new and improved version of Jinja with new features and a simpler and
faster runtime.
- JSON
- JSON, short for JavaScript Object Notation, is a lightweight computer data
interchange format. It is a text-based, human-readable format for representing
simple data structures and associative arrays (called objects).
- LAN
- Local Area Network. An interconnection of computers that are in relatively
close proximity to each other, such as within a building.
- Launchpad
- Free open-source project hosting. The repository is based on the Bazaar version control
system.
- MDAO
- Multi-disciplinary Analysis & Optimization
- metadata
- Metadata is information about an informational resource, such as a document (e.g,, a webpage), image,
dataset or other resource. It describes context, content, and structure of the resource and its
management through time.
- Method of Feasible Directions
- A gradient descent optimization algorithm used in CONMIN.
- model
- A hierarchical structure with an Assembly at its root.
- MDF
- Multidisciplinary Design Feasible. (See Multidisciplinary Design Feasible (MDF).)
- MIMO
- Multiple Inputs, Multiple Outputs
- networkx
- A Python package for creating and manipulating graphs and networks.
- NEWSUMT
- A Fortran subroutine for solving linear and nonlinear constrained or
unconstrained function minimization problems.
- NOSA
- NASA Open Source Agreement. A software license approved by the Open
Source Initiative (OSI). The National Aeronautics and Space
Administration (NASA) releases some software under this license.
- nose
- A unittest extension offering automatic test suite discovery and easy test
authoring.
- NumPy
- NumPy is the fundamental package needed for scientific computing with Python. See
http://numpy.scipy.org/
- ObjServer
- A process that allows remote connections to a Component or Container
object. An ObjServer can represent an entire model if its top-level object
is an Assembly, or it can represent a single object if its top-level object
is some other type of Component.
- ObjServerFactory
- A process that spawns a child process (ObjServer) encapsulating an
instance of a particular Component or Container type.
- OML
- Outer Mold Line
- OS
- Open Source
- OSI
- The Open Source Initiative (OSI) is a non-profit corporation formed to educate
the community about open source (OS), to advocate for the benefits of OS, and to build
bridges among different constituencies in the open-source community. For more
information, see Open Source Initiative.
- PBS
- Portable Batch System (PBS) is a queueing system. Jobs are submitted to the
queue that reflects the resources needed, and a scheduler decides which ones
to run when nodes become available. These decisions are made on the basis of
length of run, how long a job has been waiting, and fair sharing of resources
among different users.
- Paste
- Tools for using a Web Server Gateway Interface stack.
- PasteDeploy
- A tool to load, configure, and compose WSGI applications and servers.
- PasteScript
- A pluggable command-line frontend, including commands to setup package file layouts
- PID
- Process id
- PIL
- Python Imaging Library
- pip
- Installs Python packages. It is a replacement for easy_install and uses mostly
the same techniques for finding packages, so packages that were made easy_installable
should be pip-installable as well. Currently works with source distributions only.
- plugin
- An object that interacts with a host aplication to
provide specific functionality without changing the host application.
- plugins
- See plugin
- PuTTY
- A free terminal emulator application that can act as a client for SSH, Telnet,
rlogin, and raw TCP computing protocols.
- PuTTYgen
- A key generator. It generates pairs of public and private
keys to be used with PuTTY, PSCP, Plink, and the PuTTy
authentication agent, Pageant.
- Pyevolve
- A complete Python genetic algorithm framework
- Pygments
- Pygments is a syntax highlighting package written in Python.
- Pylons
- A Web framework
- pyparsing
- A Python parsing module
- PyYAML
- A YAML parser and emitter for Python.
- repository
- Bazaar term for a store of revisions. See revision.
- ResourceAllocator
- An object responsible for allocating CPU/disk resources for a particular
host, cluster, load balancer, etc.
- ResourceAllocatorManager
- An object that manages a number of child objects that are responsible for
allocating CPU and disk resources, either locally or for a particular
cluster or a particular load balancer. The RAM can be queried to determine
the current allocation of resources for the given system. This includes
host and PID information for all Components.
- ResourceDescription
- An object containing information defining system attributes required to
select a viable place to run a code.
- reStructuredText
- A plain-text markup syntax and parser system used for in-line
program documentation (such as Python docstrings), for quickly
creating simple Web pages, and for standalone documents. The
reStructuredText parser is a component of Docutils.
- revision
- Bazaar term for a snapshot of the state of files and directories, including their
content. A revision also has some metadata associated with it, including
who committed it, when it was committed, a commit message, and the
parent revisions from which it was derived.
- roman
- A Python module for roman numerals.
- Routes
- A Routing package for Python that matches URLs to dicts (dictionary network
protocols) and vice versa.
- SciPy
- SciPy (pronounced “Sigh Pie”) is open-source software for mathematics, science, and
engineering.
- ScientificPython
- A collection of Python modules that are useful for scientific computing.
- setuptools
- Tools for downloading, building, installing, upgrading, and uninstalling
Python packages.
- simplejson
- Simple, fast, extensible JSON encoder/decoder for Python.
- Sphinx
- A Python documentation generator. It translates reStructuredText markup
language into HTML. (See the Sphinx home page
for more information.)
- SQLAlchemy
- Database Abstraction Library
- Socket
- A placeholder for a plugin within a Component.
- SocketList
- A list that holds only objects that provide a particular interface.
- Sockets
- See Socket.
- SWIG
- Simplified Wrapper and Interface Generator. A software development tool that connects
programs written in C and C++ with a variety of high-level programming languages. Go to
http://www.swig.org/index.php for more information.
- Tag
- A Bazaar nickname for a particular revision. A tag is typically used to mark
a release of the software so you can easily refer to it later. Tags are stored in the
branch and are propagated when the branch is pushed, pulled or merged. If your branch is
associated with a Trac ticket, the SCM will apply a tag (corresponding to your ticket
number) when she merges your branch.
- Tempita
- Tempita is a small templating language for text substitution.
- ticket
- A ticket is a file contained within an issue (or bug) tracking system
that contains information about a request, often by an end user, to
fix a bug or make some other change to a computer software package. A
ticket has a unique reference number (ticket number) that allows the
submitter, software developer, or other technical staff to quickly
locate, add to, or communicate the status of the submitter’s issue or
request. Once OpenMDAO’s bug-tracking tool is in place, all changes to
the software will require a ticket, and the ticket number will identify
the software branch where the change is being made.
- Trac
- An open source, web-based project management and bug-tracking tool. OpenMDAO uses Trac
to track bugs, enhancements, and requirements and to host openmdao.org.
- Traits
- A software package from Enthought, Inc. A trait is
a type definition that can be used for normal Python object attributes, giving the
attributes some additional characteristics. See http://code.enthought.com/projects/traits/.
- trunk
- A Bazaar term that refers to the main development branch (in this case,
the openmdao trunk) from which working branches are pulled.
- tuple
- A tuple is an immutable list. It is defined in the same way as a list, except that the whole set of
elements is enclosed in parentheses instead of square brackets. The elements of a tuple have a defined
order, and tuples indices are zero-based, just like a list, so the first element of a non-empty tuple
is always t[0]. Negative indices count from the end of the tuple. Slicing works too, but when you
slice a tuple, you get a new tuple.
- units
- A package used by OpenMDAO that provides unit conversion capability for variables.
- Variable
- The base class used when creating a new Variable type.
- Variables
- A component’s inputs and outputs that are visible to other components
in the framework. In general, a variable is a wrapper for data
passed between framework components. It has a value, a default value,
and may contain additional attributes like upper and lower bounds and units.
Variables can also perform their own validation when being
assigned to another variable. OpenMDAO’s variables are
implemented using Traits, an open source extension to Python authored
by Enthought, Inc.
- virtualenv
- Virtualenv is a tool used to create isolated Python environments. You can
create a new Python environment to run OpenMDAO and install all package dependencies
into the virtualenv without affecting your system’s site-packages or vice versa. If you
need to upgrade a package to see how it affects your app, you can create a new
virtualenv, install/copy your app into it, run your tests, and delete it when you are
finished.
- VSP
- Vehicle Sketch Pad. VSP is a rapid geometry creation tool used to create a
wide range of aerospace vehicles from a combination of predefined components.
It provides highly interactive sketching of concepts with immediate visual
feedback.
- WebError
- A Python package for Web error handling and exception catching.
- WebHelpers
- A library of helper functions intended to make writing templates in Web applications
easier. It’s the standard function library for Pylons and TurboGears 2. It also
contains a large number of functions not specific to the Web, including text
processing, number formatting, date calculations, container objects, etc.
- WebOb
- WSGI request and response object
- WebTest
- Helper to test WSGI applications. This wraps any WSGI application and makes it
easy to send test requests to that application without starting up an HTTP
server.
- Workflow
- A Workflow controls the execution order of a group of Components. The default
workflow class is Dataflow, which orders Components based on their input and
output connections.
- WSGI
- Web Server Gateway Interface. WSGI is a standard interface for Python Web
applications to communicate with Web servers.
- YAML
- YAML is a data serialization format designed for human readability and interaction
with scripting languages.
- Zope
- Zope is an open source application server for building content management
systems, intranets, portals, and custom applications. Zope is written in
Python, an object-oriented scripting language.
- zope.interface
- A package that provides an implementation of object interfaces for Python.
