A language-independent, customisable library of fundamental physical constants sourced from NIST.
This is a little bit wheel-reinventy, there are libraries/packages out there that process the very same data I'm going to. However, one reason I wish to do this is to de-couple physical constants data from both specific languages and specific software modules dealing with other operations (such as units of measure and quantities). Aside from the obvious portability, one benefit of this is to allow tighter control over what is ultimately an input dataset within a given project:
- If the dataset changes (improved accuracy, updated standard values, bug fixes etc.) this is a change occurring under the auspice of the project and its revision control system, not in the background.
- It may be desirable to maintain references to a specific dataset in a revision-controlled codebase, something less easy to do if the dataset is managed as an external package.
None, standard library only.
The following assuumes bin/codata is in the system PATH.
The utility currently writes to STDOUT, so for now it's for use with
pipes and redirection:
codata > /path/to/output/file
Search constants database for substrings. This is not intelligent, so if you want a specific constant it's best to make sure the substring is unique to it via quotation (note the usual shell behaviour of unpreserved spaces, so if the substring has spaces, it requires quote-delimiting).
codata -s light standard 'molar mass constant'
Different output formats can be selected, currently CSV and XML:
codata -f xml 'standard-state pressure'
codata -f csv 'standard-state pressure'
CSV is the default at the moment, but will be replaced by a plain text representation at Some Point(tm). The XML is rough and ready but should be enough for now.
This is going to start simple and be extended incrementally as and when I find a personal need.
- Subset categories.
- Subset specification.
- More data format choices.