For molecular modelers working with SAMSON, understanding the intricate details of the Node Specification Language (NSL) can significantly enhance modeling efficiency. One feature that often perplexes users but proves incredibly useful is the handling of path attributes. This blog post covers everything you need to know about path attributes in NSL, helping you better define and work with conformation nodes in your projects.
Introduction to Path Attributes
The path attribute space (short name: p) is designed specifically for conformation nodes. It provides a structured way to filter, organize, and manipulate paths based on their characteristics. Attributes for paths can be inherited from the more general node attribute space or defined specifically for path.
Why Are Path Attributes Important?
Managing molecular conformations often requires precise selection criteria, whether you are isolating a specific group of paths based on their names, filtering paths by the number of atoms, or working with selection flags. Instead of manually sifting through data, you can use tailored expressions to quickly identify and act on the information you need, streamlining research workflows.
Key Path Attributes in NSL
Inherited Path Attributes
Some attributes associated with path are inherited from node. Here are the most notable:
- Name (
p.n): Filter paths based on their names, which are strings enclosed in quotes. For instance:
|
1 |
p.n "A" |
|
1 |
p.n "L*" |
The second example uses a wildcard to match any name starting with “L.” This flexibility is particularly helpful when naming conventions are used in datasets.
- Selection (
p.selected): Use this attribute to match selected or unselected nodes.
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1 |
p.selected |
|
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not p.selected |
Whether you’re zeroing in on currently selected elements or excluding them, this attribute makes the operation quick and precise.
- SelectionFlag (
p.sf): Likeselected, this attribute filters based on selection flags, with possible values oftrueorfalse.
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p.sf false |
Specific Path Attributes
path.numberOfAtoms (p.nat) is a path-specific attribute that lets you filter paths by their number of atoms. This is particularly useful when dealing with datasets of varying molecular sizes. For example:
- Filter paths with more than 100 atoms:
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1 |
p.nat > 100 |
- Select paths with 100 to 200 atoms:
|
1 |
p.nat 100:200 |
These expressions eliminate the need to manually identify paths, saving valuable time while ensuring accuracy in your selection.
Conclusion
Path attributes, whether inherited or specific, serve as a powerful toolkit for molecular modelers using SAMSON. They enhance the precision and efficiency of working with conformation nodes, giving you greater control over your data manipulation. To explore these attributes further, visit the full documentation at this link.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can download SAMSON at https://www.samson-connect.net.