esbmtk 0.4.0.2

An Earth Sciences Box Modeling Toolkit

Table of Contents

1. ESBMTK - An Earth-sciences box modeling toolkit
2. News
3. Contributing
4. Installation
5. Documentation
6. Todo
7. License

ESBMTK - An Earth-sciences box modeling toolkit

ESBMTK is python library which aims to simplify typical box modeling projects the in Earth-Sciences. The general focus is to make box modeling more approachable for classroom teaching. So performance and scalability currently no priority. Specifically, the solver is just a simple forward Euler scheme, so stiff problems are not handled gracefully.

At present, it will calculate masses/concentrations in reservoirs and fluxes including isotope ratios. It provides a variety of classes which allow the creation and manipulation of input signals, and the generation of graphical results.

News

• March 18^th esbmtk 0.4.0.0 now has a carbonate chemistry module which currently includes methods to calculate PCO₂, CA, and H⁺ concentrations from TA and DIC. The seawater class has been renamed SeawaterConstants and provides access to a limited set of seawater species concentrations and their K and Pk constants at given set of temperature, salinity and pressure conditions. This version also includes some refactoring in the Connnection and ConnectionmGroup classes. It is likely that this broke some connection types.

• March 13^th, cleaned up the use of the k_value keyword which is now restricted to the flux_balance connection type. In all other instances use the scale keyword instead. The old keyword is still working, but will print a warning message. The describe() method is now called info().

• March 11^th, added a seawater class which provides access to K-values, and concentrations.

• March 10^th, the code documentation is now available at https://uliw.github.io/esbmtk/esbmtk/index.html

• March 6^th, the plot reservoir function now takes and additional filename argument e.g., (fn="foo.pdf"). Signals now accept an optional reservoir argument. This simplifies signal creation as the source and reservoir connection can be created implicitly.

• Feb. 28^th, added a VirtualReservoir class. This class allows the definition of reservoirs which depend on the execution of a user-defined function. See the class documentation for details.

  Display precision can now be set independently for each Reservoir, Flux, Signal, Datafield and VirtualReservoir

• Jan. 30^th, added oxygen and nitrogen species definitions

• Jan. 18^th, Reading a previous model state is now more robust. It no longer requires the models model have the same numbers of fluxes. It will attempt to match by name, and print a warning for those fluxes it could not match.

• Jan. 12^th, The model object now accepts a plot_style keyword

• Jan. 5^th, Connector objects and fluxes use now a more consistent naming scheme: Source_2_Sink_Connector, and the associated flux is named Source_2_Sink_Flux. Processes acting on flux are named Source_2_Sink_Pname

  The model type (m_type) now defaults to mass_only, and will ignore isotope calculations. Use m_type = "both" to get the old behavior.

• Dec. 30^th, the connection object has now a generalized update method which allows to update all or a subset of all parameters

• Dec. 23^rd, the connection object has now the basic machinery to allow updates to the connection properties after the connection has been established. If need be, updates will trigger a change to the connection type and re-initialize the associated processes. At present this works for changes to the rate, the fractionation factor, possibly delta.

• Dec. 20^th, added a new connection type (flux_balance) which allows equilibration fluxes between two reservoirs without the need to specify forward and backwards fluxes explicitly. See the equilibration example in the example directory.

• Dec. 9^th, added a basic logging infrastructure. Added describe() method to Model, Reservoir and Connnection classes. This will list details about the fluxes and processes etc. Lot's of code cleanup and refactoring.

• Dec. 7^th, When calling an instance without arguments, it now returns the values it was initialized with. In other words, it will print the code which was used to initialize the instance.

• Dec. 5^th, added a DataField Class. This allows for the integration of data which is computed after the model finishes into the model summary plots.

• Nov. 26^th Species definitions now accept an optional display string. This allows pretty printed output for chemical formulas.

• Nov. 24^th New functions to list all connections of a reservoir, and to list all processes associated with a connection. This allows the use of the help system on process names. New interface to specify connections with more complex characteristics (e.g., scale a flux in response to reservoir concentration). This will breaks existing scripts which use these kind of connections. See the Quickstart guide how to change the connection definition.

• Nov. 23^rd A model can now save it's state, which can then be used to initialize a subsequent model run. This is particularly useful for models which require a spin up phase to reach equilibrium

• Nov. 18^th, started to add unit tests for selected modules. Added unit conversions to external data sets. External data can now be directly associated with a reservoir.

• Nov. 5^th, released version 0.2. This version is now unit aware. So rather than having a separate keyword for unit, quantities are now specified together wit their unit, e.g., rate = "15 mol/s". This breaks the API, and requires that existing scripts are modified. I thus also removed much of the existing documentation until I have time to update it.

• Oct. 27^th, added documentation on how to integrate user written process classes, added a class which allows for concentration dependent flux. Updated the documentation, added examples

• Oct. 25^th, Initial release on github.

Contributing

Don't be shy. Contributing is as easy as finding bugs by using the code, or maybe you want to add a new process code? If you have plenty of time to spare, ESMBTK could use a solver for stiff problems, or a graphical interface ;-) See the todo section for ideas.

Installation

ESBMTK relies on the following python versions and libraries

• python > 3.6
• matplotlib
• numpy
• pandas
• typing
• nptyping
• pint

If you work with conda, it is recommended to install the above via conda. If you work with pip, the installer should install these libraries automatically. ESBMTK itself can be installed with pip

• pip install esbmtk

Documentation

The documentation is available in org format or in pdf format. See the documentation folder, specifically the quickstart guide.

At present, I also provide the following example cases (as py-files and in jupyter notebook format)

• A trivial carbon cycle model which shows how to set up the model, and read an external csv file to force the model.

Todo

• expand the documentation
• provide more examples
• do more testing

License

ESBMTK: A general purpose Earth Science box model toolkit Copyright (C), 2020 Ulrich G. Wortmann

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.