Quantities and Units

One of the main goals of the CSD model is that the datasets are self contained to simplify sharing of scientific data. An essential part of achieving this goal is that all quantities in a dataset are specified as proper scientific quantities, i.e. as a number and a unit. The use of quantities is integrated in all parts of CSDM.

The supporting material of the CSDM paper give an extended overview of the units and quantities allowed in CSDM. Here is a brief summary of the quantities allowed in CSDM. Note that the current JavaScript implementation does not give correct units of dimensionless units arising from ratios of quantities, such as the plane angle with dimensionality L/L.

Test the unit parser here:

We are currently preparing generic libraries to handle quantities in other applications. You can see the status below.

Language	Implemented	Available	Comment
Python	😀	😀	The csdmpy package is available.
JavaScript	😀	😀	Debugging is still undergoing, but take a preview at gitlab.
Tcl	😀	😐	As part of the SIMPSON implementaion of CSDM, we are developing a Tcl interface that is still under development.
Obj-C	😀	😀	Units and quantities are supported by RMN and PhySyCalc. The libraries are not available for download.
C	😡	😡	We are planning to translate the JavaScript implementation into a C library. More information will become available here later.

😀: Fully implemented

😐: Partially implemented

😡: Not implemented

The entries of the table are the allowed quantities in CSDM.

Quantity	SI unit	Dimensionality

As part of the quantities above, CSDM accepts a number of other physical symbols as listed in the table below.

Name	Symbol	Value in SI units