Conventions

Following in Section II.b is a alphabetic list of the LaGriT commands. Conventions that apply to all commands include:

1.   Lines are a maximum of 80 characters long, identifiers are a maximum of 32 characters long.

2.   Continuation lines are signaled by an “&” as the last character of a line to be continued. A command can be up to 1024 characters long.

3.   Delimiters are comma, slash, equal sign, or blank. (‘,’ ‘/’ ‘=’’ ‘).

Blanks on either side of other delimiters are ignored. Leading blanks are ignored. Commas are usually used for parameters that belong to the same logical set such as first point, last point, stride. Slashes are usually used to separate sets of parameters.

4.   The three parameters: first point, last point, stride can have integer values which refer to actual sequential point numbers or they can have the character- string values:

pset, get, name where name has been defined by a previous pset command.

The triplet: 1, 0, 0 refers to all points.

The triplet: 0, 0, 0 refers to the set of points defined in the last geometry command.

5 . Commands should be typed in lower case, however names are case sensitive.

In the command description that follows certain symbols have special meaning.

[ ]          surround optional parameters

             signifies alternate choices

, or /      separates parameters

___        underline specifies default

6 . Courier font is used for variable names such as ifirst.

bold is used for literal keywords such as xyz.

7 . Comments are identified by

  1. All names ( surface, region, pset,…) should be limited to 32 characters.

  2. The right hand rule is used to determine normals to planes and to sheet surfaces. The first two points determin the first vector and the first and third point determine the second vector. By curling the fingers of the right hand from the first vector toward the second vector, the right thumb will point in the direction of the normal.

“1” “148”

10 . To separate commands on the same line use a semicolon (;).

  1. Three coordinate systems are used.

xyz refers to the standard Cartesian coordinate system

rtz refers to a cylindrical coordinate system aligned along the z-axis, where r is the radius measured from the zaxis, t (theta) is the angle measured in the xy-plane from the positive x-axis toward the positive y-axis and z is the height measured from the xy-plane.

rtp refers to a spherical coordinate system, where r is the radius measured from the origin, p (phi) is the angle in the xy-plane measured from the positive x-axis toward the positive y-axis, t (theta) is the angle measured from the positive z-axis to the positive y axis.

“411” “264”