Library Model Files

Library models are stored as plain text files. For example, the Cumulative Normal Distribution model file, Cnorm.lbm, contains the lines:

;Cumulative Normal Distribution
Cnorm(z):=integral(Normal(x),x,-infinity,z)
Normal(x):=1/sqrt(2PI)*E^-(x^2/2)

All text in a line following a semicolon (;) is a comment. All remaining lines are definitions exactly as they would be typed in the Tree Editor's Formula Bar.

Because library model files are stored as plain text, you can edit or create these files directly using any text editor or standard word processor.

Note: If you edit LBM files using a word processor, the modified file must be saved as plain text, not in the word processor's native format.

The first line in an LBM file is usually a comment that is used as a description in the Library Model List. You create this comment by attaching a comment to the root node in the Tree Editor. When LBM files are loaded back into the Tree Editor, comments are attached to the first node whose definition follows each comment.

The first definition in an LBM file is the model's root node definition. The remaining lines contain other node definitions and associated comments in any order.

Multiple Line Definitions

In LBM files, definitions can occupy several lines to improve readability. As DecisionPro reads lines, it assumes that if the definition on the current line does not have all quotation marks, brackets, braces, and parentheses matched up, the following line must be appended. For example, the definition

f(x):=(
x^2
)

is equivalent to

f(x):=(x^2)

However, note that the definition

f(x):=
(
x^2
)

is equivalent to two expressions

f(x):=

and

(x^2)

The line f(x):= has all quotation marks, brackets, braces, and parentheses matched up so it is assumed to be a complete expression.