Black Box 4/BlackBox.cdr/autocad/param2.arj/GLOSSARY

Text File | 1991-09-02 | 12.3 KB | 280 lines

 ParaDraft Glossary                Copyright 1991, ParaWare Systems

           GLOSSARY (Sorted alphabetically)

Center line layer - Layer in which the center lines are drawn. Must
be unique.

Customization - Changing the application generated by ParaDraft so
that it is easier to use and has formulae built-in specific to your
problem.

Data Table - Rows and columns of values, where each column has
a name that describes the type of value, and each row constitutes a
set of values. A natural way of describing standard values, often
used by engineers.  Given values for one or more columns, matching
row can be searched and the rest of the standard values can be
picked from it.

Dimension - A distance, angle, radius or diameter shown on a drawing
using AutoCAD dimensioning commands.

Dimension text - Text that appears with the dimension

Dimension value - Value assigned to a dimension while creating an
instance of parametric geometry with a PgProgram

Dimensioning layer - Layer used for dimensioning entities such as
dimensions, extension lines etc

Entities - Geometric entities; LINE, CIRCLE, ARC are the
supported AutoCAD entities.

Existing drawings - Detailed drawings already created using AutoCAD
before ParaDraft was used. Can be used as the specification of the
parametric geometry, i.e. as Parent Geometry

Explanation - Reasoning used for parameterisation of a particular point.

Exploded Dimensions - Dimensions that are not a single entity in the
AutoCAD drawing rather are just a collection of lines, solids, arc
and text entities

Extension Lines - Lines used to indicate that a point actually
lies on the extension of another line, for the purpose of
parameterisation. Often used with corner points. All additional
extension lines must actually pass through the target point to be
effective for parameterisation.

Family of Parts - Anytime similar geometry with modifications
describes a group of objects they belong to a family. The parts
which are similar in shape but differ in sizes are called a family
of parts.

Feasible parameterisation - When all points required to draw the
parametric geometry have been defined using more than one entity.

Formula - an algebraic expression involving constants, variables,
functions  and operators, that evaluates to a unique value.

Geometric reasoning - Reasoning based on geometric theorems and
equations.  Applied to arrive at geometric relationships, which are
then used for geometry parameterisation.

Geometry - A collection of geometric entities as LINE, CIRCLE, ARC etc.
Also see Parametric Geometry, Parent Geometry, Instance Geometry.

Geometry Name - Name used for a ParaDraft application or a PgProgram.
Also used for PGCAL/GW-BASIC/Turbo-Pascal programs for an application.
Must be a valid AutoCAD drawing file name.

Header row - Row that defines the names of the columns in a data table.

Heuristics - Rules based on experience. ParaDraft uses heuristics
to understand parent geometry, that are listed in the Appendix C.

Initialization Script File - An AutoCAD script file created by the
ParaDraft installation program. Used to load ParaDraft using SCRIPT
command. The file is called PGINIT.SCR and is in the ParaDraft
directory and its parent directory as well.

Input Drawing - see Parent geometry

Input parameter - Parameter whose value is given by the user of a
ParaDraft application

Insertion angle - Angle at which the entire instance geometry drawn
by a ParaDraft application is rotated, including the dimensioning,
hatching and annotations.

Insertion point - Point at which the reference point of the instance
geometry drawn by a ParaDraft application is placed.

Instance geometry - A to-the-scale geometry drawn by a user or a
program from the parametric geometry corresponding to a given set of
parameter values.

Layer Convention - A naming convention of layers describing the
layers to which the entities making up the parent geometry belong

Leader dimension - A dimension that points at a feature of the
parent geometry and describes it using text. For example, "4 HOLES,
DIA 10", "Chamfer 1x45" etc. Not supported by ParaDraft, and ignored
forthe purpose of parameterisation of geometry.

Offset geometry - A continuous shape that can be drawn in the
instance geometry using a polyline as an offset of another polyline
and a linear dimension that specifies the offset distance and
direction.

Paradraft Application- see Parametric Drafting Application.

Paradraft commands - Commands understood by AutoCAD drawing editor,
once ParaDraft has been loaded using the initialization script file.
All ParaDraft command names start with the string "PG", which is
pronounced as Pee Gee. For example, PGDRAW is pronounced as Pee Gee Draw.

Parameterisation - Creation of the parametric geometry program
from the input drawing. This is done by arriving at the expressions
for calculating coordinates of the points needed to draw the
parametric geometry. For example, the program for the parallelogram
in the tutorial has expressions to calculate the four corner points
of the parallelogram, which is drawn by connecting the four by lines.

Parameterisation assumption - An additional parameter
automatically created during parameterisation by PgPg!, which is
assumed as the X or Y coordinate of a point. An assumption is made
when PgPg! cannot find expressions for the coordinates of one or more
points using the given parent geometry and its dimensioning scheme.

Parameterisation unsuccessful - PgPg! discontinues parameterisation
and generates no application. It happens when one of the points that
is required for the parametric geometry to be drawn, lies on only one
entity. From this PgPg! concludes that the point can not be
parameterised and further efforts are futile.

Parameters - Variables controlling a parametric geometry.
Changing the value of a parameter has the effect of changing the
shape or the size of the resulting instance geometry.

Parametric Drafting - Automatic creation of drawings from the values
of the dimensions using parametric geometry techniques.

Parametric Drafting application - accepts the values of input
parameters and draws the to-the-scale instance geometry
automatically, optionally hatched, dimensioned and annotated. It is
made up of a set of programs for the parametric geometry that work
together.

Parametric Geometry Program - A program for a Parametric Geometry
that accepts the values of all the dimensions and draws the
to-the-scale corresponding instance geometry.  ParaDraft refers to
these programs as PgPrograms.

Parametric geometry - A generalized geometry that defines a family of
geometries (or parts) with same shape, but with different sizes. In
fact, every dimensioned drawing represents a parametric geometry,
where the dimensions can be varied to get geometries of different sizes.

PARENT - A ParaDraft command for processing the Parent Geometry for
presenting it to PgPg! for parameterisation. Requires PGPG to be loaded.

Parent geometry - Input drawing that specifies the Parametric
Geometry to PgPg!. It consists of the most general instance geometry
of the Parametric Geometry, dimensions to be used as parameters, and
a reference point. It also may have extension lines, center lines
and symmetry information to facilitate parameterisation. You should
draw Parent Geometry accurately and carefully such that it conveys
your intention unambiguously to PgPg!. Given the parent geometry a
draughtsperson should be able to draw a to-scale drawing for any set
of dimension values uniquely.

PGCAL - A simple and easy-to-use formula calculator integrated with
PGRUN for customizing the generated PgPrograms. Also a ParaDraft
command of the same name for testing the formulae.

PGCUSTOM - A set of ParaDraft commands used for refining the
user interface of ParaDraft applications.  Also a ParaDraft command of
the same name for defining an AutoCAD command for the application.

PGDATA -  A ParaDraft command for editing the data table files. Loads
the table file into your favorite editor for editing.

PGDEBUG - A ParaDraft command for graphically presenting the
problems of parameterisation in a PgProgram. It also provides the
explanation for the parameterisation of each point. The explanation
can be displayed using DDATTE command by clicking at the point.

PGDIR - A ParaDraft command for finding the names of the available
applications. Accepts wild cards as * and ? in the names.

PGEDIT - A ParaDraft command for editing the PGCAL or GW-BASIC files.
Loads the file into your favorite editor.

PGMSLIDE - Overwrites the slide file, that is displayed for taking the
inputs along with an application, with the current display. Be
careful since you lose the original slide file.

PgPg! - The Geometry Parameterisation Expert System. The name stands
for Parametric geometry Program generator.
PgPg! accepts the parent geometry as the specification of
parametric geometry, and converts it into the corresponding PgProgram
written in AutoLISP. It also creates the template files for the PGCAL
and GW-BASIC interfaces.

PGPG - AutoLISP part of Parent Geometry Specification Program, that
processes the Parent Geometry and presents it to PgPg!. Also a
ParaDraft command of the same name to load the Parent Geometry
Specification Program.

PgProgram - see Parametric Geometry Program

PGPGSET - A ParaDraft command for defining the names of dimensioning
and center line layers.  Also to define how to run PgPg! program.
Setting are valid only for a session. Requires PGPG to be loaded.

PGRUN - Runtime system of ParaDraft. Consists of AutoLISP functions,
PGCAL program, and PGCUSTOM utility. Defines a set of ParaDraft
commands used for running and customizing ParaDraft applications.
Also a ParaDraft command of the same name for loading the runtime
system.

PGSET command - A ParaDraft command for defining how the dimension
values should be obtained for the PgPrograms. Setting are valid only
for a session. Requires PGRUN to be loaded.

PGSHOW - A ParaDraft command for seeing the slide file for a
ParaDraft application

PICKFROM - PGCAL command for performing a table lookup. Takes the
name of the table as the parameter. The table should be in the
ParaDraft directory.

Points - All parametric geometric entities are described using
 points which are generated automatically by PgPg!.  Explanation of
parameterisation of all points is provided. See PGDEBUG.

Polyline - AutoCAD polyline entity made up of lines and arcs.
Polyline found in parent geometry is considered as a special entity
by ParaDraft. It can be used for defining hatching and offset geometry
in the ParaDraft Professional.

Problem point - A point that can not be parameterised by PgPg!.

Reference point - A user specified point on the parent
geometry. While drawing the instance geometry, it is placed at the
given insertion point. It should be possible to relate all other
points defining the parametric geometry to this point since
geometry is parameterised starting from this point.

Symmetry axis - A center line in the parent geometry. Specified
by user along with the range of influence of symmetry.

Tables -  see Data Tables

Template file - Files created by PgPg! to simplify customization of
ParaDraft applications. You can change these for customizing the
PgProgram using PGCAL, GW-BASIC interface or Turbo-Pascal interface.
Without changes they can be used for drawing the instance geometry
with the default values.

Temporary variables - A variable in the PGCAL program, whose
value is not used by the PgProgram.

To-the-scale drawing - has the geometry drawn exactly as per
the dimensions. Such a drawing can be directly used for planning and
manufacturing purposes.

Unspecified fillet radius - A default radius value specified
for the fillets by a radial dimension for one of the fillets in the
parent geometry. It is identified by adding a suffix of "TYP."
(typical) to the dimension text.  All fillets with the same radius as
the one so dimensioned will take this input value.

Value rows - Rows that define sets of values for each of the
columns in a data table

Variables for dimensions - A variable in the PGCAL program,
whose value is used by the PgProgram for a dimension in the
parametric geometry, with the same name.