About luox
A user-friendly, open-access platform for calculating quantities related to light and lighting
- About
- Purpose
The purpose of the luox platform is to faciliate the calculation of quantities related to light and lighting in a user-friendly, open-access and free fashion. Users can upload spectra (which are only stored in the browser) and the platform will calculate relevant quantites (including (il)luminance, chromaticity, and α-opic (ir)radiance and α-opic daylight (il)luminances) from the spectra, generate a visualisation of the spectrum, and enable the export of calculations in tabular form. All default quantities reported here are supported by the International Commission on Illumination (CIE).
The platform is primarily geared towards researchers and research users interested in the effects of light exposure on human physiology and behaviour, but it may be interesting to students, academics and professionals in other disciplines and areas.
luox is deployed on Netlify.
- Team
This platform was developed by Prof. Dr. Manuel Spitschan (Technical University of Munich and Max Planck Institute for Biological Cybernetics) and Go Free Range. Code to calculate colour indices was developed by Dr. Somang Nam and Dr. Jennifer A. Veitch at the National Research Council of Canada – Construction Research Centre, in collaboration with Dr. Spitschan.
- Citing
If you use luox for calculations, please cite the following (APA format):
Software:
Spitschan, M., Nam, S., & Veitch, J. A. (2022). luox: Platform for calculating quantities related to light and lighting [Software]. Available from https://luox.app/.
Companion paper:
Spitschan, M., Mead, J., Roos, C., Lowis, C., Griffiths, B., Mucur, P., Herf, M., Nam, S., & Veitch, J. A. (2022). luox: novel validated open-access and open-source web platform for calculating and sharing physiologically relevant quantities for light and lighting. Wellcome Open Res, 6, 69. doi:10.12688/wellcomeopenres.16595.3
For citing the source code:
Spitschan, M., Nam, S., & Veitch, J. A. (2022). luox: Platform for calculating quantities related to light and lighting [Source code]. Available from https://github.com/luox-app/luox.
When reporting quantities related to CIE S 026, we also recommend citing the standard:
CIE (2018). CIE S 026/E:2018: CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light. Vienna: CIE Central Bureau. DOI: 10.25039/S026.2018.
When citing other outputs from this software, we recommend citing the appropriate documents, listed below.
- Support
For any support-related questions, please email luox-support@tuebingen.mpg.de. Please be as specific as possible in your request.
- Bug reports and feature requests
To report bugs and suggest new features, please raise an issue on the project's GitHub page. When reporting a bug or any other issue, you need to be as specific as possible:
- Include concrete and specific steps to reproduce your problem, including any files that pose an issue
- If the problem only occurs occasionally but is reproducible, please include any additional contextual information
- If the problem is not reproducible, it may not be useful to submit a bug report
- Funding
Funding to develop luox was provided by:
- Wellcome Trust (Research Enrichment – Open Research, 204686/Z/16/C);
- Society of Light & Lighting (2020 Jean Heap Bursary);
- van Houten Fund of the University of Oxford (VH-148).
The development of the module for loading SPDX files was supported by the Illumating Engineering Society (IES).
During development of the platform, Dr Manuel Spitschan was supported by a Sir Henry Wellcome Postdoctoral Fellowship (Wellcome Trust, 204686/Z/16/Z) and Linacre College, University of Oxford (Biomedical Sciences Junior Research Fellowship).
The module for calculating CIE colour indices (Duv, Tcp, Ra, and Rf ), the power user mode, and the optional IES TM-30-20 indices and graphics was developed at the National Research Council of Canada, Construction Research Centre, as a strategic research activity.
Deployment on Netlify is supported by the Netlify Open Source Plan.
- Contributing code of conduct
We welcome contributions. To contribute code, please create a fork and issue a pull request on GitHub.
Contributor Covenant Code of Conduct
Our Pledge
We as members, contributors, and leaders pledge to make participation in our community a harassment-free experience for everyone, regardless of age, body size, visible or invisible disability, ethnicity, sex characteristics, gender identity and expression, level of experience, education, socio-economic status, nationality, personal appearance, race, caste, color, religion, or sexual identity and orientation.
We pledge to act and interact in ways that contribute to an open, welcoming, diverse, inclusive, and healthy community.
Our Standards
Examples of behavior that contributes to a positive environment for our community include:
- Demonstrating empathy and kindness toward other people
- Being respectful of differing opinions, viewpoints, and experiences
- Giving and gracefully accepting constructive feedback
- Accepting responsibility and apologizing to those affected by our mistakes, and learning from the experience
- Focusing on what is best not just for us as individuals, but for the overall community
Examples of unacceptable behavior include:
- The use of sexualized language or imagery, and sexual attention or advances of any kind
- Trolling, insulting or derogatory comments, and personal or political attacks
- Public or private harassment
- Publishing others' private information, such as a physical or email address, without their explicit permission
- Other conduct which could reasonably be considered inappropriate in a professional setting
Enforcement Responsibilities
Community leaders are responsible for clarifying and enforcing our standards of acceptable behavior and will take appropriate and fair corrective action in response to any behavior that they deem inappropriate, threatening, offensive, or harmful.
Community leaders have the right and responsibility to remove, edit, or reject comments, commits, code, wiki edits, issues, and other contributions that are not aligned to this Code of Conduct, and will communicate reasons for moderation decisions when appropriate.
Scope
This Code of Conduct applies within all community spaces, and also applies when an individual is officially representing the community in public spaces. Examples of representing our community include using an official e-mail address, posting via an official social media account, or acting as an appointed representative at an online or offline event.
Enforcement
Instances of abusive, harassing, or otherwise unacceptable behavior may be reported to the community leaders responsible for enforcement via email at manuel.spitschan@tum.de. All complaints will be reviewed and investigated promptly and fairly.
All community leaders are obligated to respect the privacy and security of the reporter of any incident.
Enforcement Guidelines
Community leaders will follow these Community Impact Guidelines in determining the consequences for any action they deem in violation of this Code of Conduct:
1. Correction
Community Impact: Use of inappropriate language or other behavior deemed unprofessional or unwelcome in the community.
Consequence: A private, written warning from community leaders, providing clarity around the nature of the violation and an explanation of why the behavior was inappropriate. A public apology may be requested.
2. Warning
Community Impact: A violation through a single incident or series of actions.
Consequence: A warning with consequences for continued behavior. No interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, for a specified period of time. This includes avoiding interactions in community spaces as well as external channels like social media. Violating these terms may lead to a temporary or permanent ban.
3. Temporary Ban
Community Impact: A serious violation of community standards, including sustained inappropriate behavior.
Consequence: A temporary ban from any sort of interaction or public communication with the community for a specified period of time. No public or private interaction with the people involved, including unsolicited interaction with those enforcing the Code of Conduct, is allowed during this period. Violating these terms may lead to a permanent ban.
4. Permanent Ban
Community Impact: Demonstrating a pattern of violation of community standards, including sustained inappropriate behavior, harassment of an individual, or aggression toward or disparagement of classes of individuals.
Consequence: A permanent ban from any sort of public interaction withi the community.
Attribution
This Code of Conduct is adapted from the Contributor Covenant version 2.0.
Community Impact Guidelines were inspired by Mozilla's code of conduct enforcement ladder.
For answers to common questions about this code of conduct, see the FAQ. Translations are available.
- Purpose
- Usage
- Quick start
We provide a documented wizard for uploading your files to the platform.
- Sharing spectra and calculations using sharing URL
Spectra and calculations within the luox platform can be shared using an URL that directly encodes the uploaded spectrum/spectra using Michael Herf's spdurl package. The sharing URL will open a view-only version of the platform. To copy the sharing URL, scroll down to the bottom of the page. Before sharing the URL, please double-check that it opens spectrum/spectra as expected.
- Requesting DOI for sharing URL
We offer the option to request a digital object identifier (DOI) linked to the sharing URL. This DOI has to be requested manually and the request will be vetted manually. To request a DOI, please complete this form. The DOI will be generated by generating an entry for the sharing URL in the MPG.PuRE and author information will be included in the record. All luox sharing URLs added to ORA will receive a unique luox number of the format (
YYYY-####
;Y
=year). A running list of luox sharing URLs with associated DOIs is on this page, under Depositions. Please note that deposition of the sharing URL into MPG.PuRE is permanent.
- Quick start
- Deposition
- List of depositions
The following is a list of depositions with assigned DOIs, up-to-date as of 1 February 2022.
Deposition ID Date DOI Depositor luox-2021-0001 23 January 2021 TBD Manuel Spitschan, University of Oxford luox-2021-0002 18 February 2021 10.5287/bodleian:AeZAXN1km Jan-Frieder Harmsen, Maastricht University luox-2021-0003 18 February 2021 10.5287/bodleian:dp7QEqYAm Jan-Frieder Harmsen, Maastricht University luox-2021-0004 18 February 2021 10.5287/bodleian:0ogQP5bb5 Jamie Zeitzer, Renske Lok & Daniel Joyce, Stanford University luox-2022-0001 01 February 2022 10.17617/2.3364820 Boris Hanák, Spectrasol luox-2022-0002 01 February 2022 10.17617/2.3364831 Jamie Zeitzer, Stanford University
- List of depositions
- Under the hood
- Calculation definitions
All default calculations performed here follow guidance from the International Commission on Illumination (CIE).
Indices that are undefined for a given test spectrum return a value of N/A. For example, colour rendering and colour fidelity are defined only when |Duv| < 0.05.
- Precision and decimal points
All calculations are computed with double-precision floating point numbers using JavaScript. In the browser, the results are displayed up to four decimals for all quantities (including those in Advanced mode). When downloading calculations, the precision will be higher than displayed in the browser. The possible ranges of numbers which can be represented under the double precision will then be limited to approximately 16 decimal places of precision. The calculations in _luox_ follow the published documents strictly, including any guidance concerning rounding at intermediate stages. This can introduce what appear to be rounding errors when compared to other calculation tools. In order to mitigate this issue and to maximise transparency, _luox_ provides an option to display all intermediate values in the calculation, in which can be useful to track down errors.
- Effect functions and action spectra
Name Source document Wavelength spacing/range [nm] CIE 1931 xy (2°) ISO/CIE 11664-1:2019, Table 1 (p. 10-21) 1 / 360-830 CIE 1964 xy (10°) ISO/CIE 11664-1:2019, Table 2 (p. 22-32) 1 / 360-830 CIE S 026/E:2018 a-opic action spectra CIE S 026/E:2018, Table 2 (p. 12-21) 1 / 380-780 Note: The CIE S 026/E:2018 a-opic action spectra are available in tabulated form from the CIE website (Internet Wayback Machine).
- Illuminant data
Name Source document Wavelength spacing/range [nm] Standard illuminant A ISO 11664-2:2007/CIE S 014-2:2006, Table 1 (p. 7-12) 1 / 300-830 Standard illuminant D65 ISO 11664-2:2007/CIE S 014-2:2006, Table 1 (p. 7-12) 1 / 300-830 Illuminant C CIE 015:2018, Table 5 (p. 51-53) 5 / 300-780 Illuminant D50 ISO/CIE 11664-2:2022(E), Table A.1 (p. 8-14) 1 / 300-830 Illuminant D75 CIE 015:2018, Table 5 (p. 51-53) 5 / 300-780 Illuminants F1-F12 CIE 015:2018, Table 10.1 (p. 59-60) 5 / 380-780 Illuminants FL3.1-FL3.8 CIE 015:2018, Table 10.2 (p. 61-62) 5 / 380-780 Illuminants FL3.9-FL3.15 CIE 015:2018, Table 10.3 (p. 63-64) 5 / 380-780 Illuminants HP1-HP5 CIE 015:2018, Table 11 (p. 65-66) 5 / 380-780 Illuminants LED-B1-LED-B5 CIE 015:2018, Table 12.1 (p. 67-68) 5 / 380-780 Illuminants LED-BH1, LED-RGB1, LED-V1, LED-V2 CIE 015:2018, Table 12.2 (p. 69-70) 5 / 380-780 - References to official documents
- CIE 224:2017: CIE 2017 Colour Fidelity Index for accurate scientific use
- CIE 015:2018: Colorimetry, 4th Edition, DOI: 10.25039/TR.015.2018
- ISO 11664-2:2007/CIE S 014-2:2006: Colorimetry — Part 2: CIE Standard Illuminants
- CIE S 026/E:2018: CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light, DOI: 10.25039/S026.2018
- CIE 13.3-1995 : Method of measuring and specifying colour rendering properties of light sources
- IES TM-30-20: IES method for evaluating light source color rendition
- Implementation specifics
While calculation procedures are structurally well-defined by the CIE, there are a few ambiguities that may arise when implementing it. This includes the choice of specific and exchangeable algorithms (e.g. for the calculation of CCT), and the decimal points of specific constants. The specific choices are described here:
Aspect Quantity Method or quantity used in luox Description Constant for absolute (il)luminance conversion Illuminance [lx] and Luminance [cd/m2] 683.0015478 lm/W 683 lm/W acceptable "for all practical applications" according to ISO 23539:2005/CIE S 010:2004, 683.0015478 lm/W exact value used in the CIE S 026 toolbox; usually rounded up to 683.002 lm/W Rounding CIE colour rendering index Ra Strict rounding after calculating subindices Following CIE 13.3-1995, luox rounds to the nearest whole number after calculating the subindex for each of the special colour rendering indices, and then averages them to form the General Colour Rendering Index - Source code availability and license
The source code is available on GitHub (https://github.com/luox-app/luox/) under the GNU General Public License v3.0.
- Validation
The default output of luox (CIE quantities and indices) has been validated by the CIE. The validation report is available here.
According to the CIE:
This software incorporates methods, formulae, spectral function calculations and spectra from the International Commission on Illumination (CIE). The CIE endorses this software having made a black-box evaluation of the software as of Feb. 11, 2021, finding that the software performs satisfactorily to calculate quantities and indices derived from CIE publications. This software is not a replacement for the CIE publications and works from which it is derived. The user is advised to consult the original publications and works for proper understanding of and calculation of the result of this software.
This software has been validated to load SPDX files according to TM-27-20.
This software offers optional calculation of indices from IES TM-30-20. These optional calculations have not been validated.
- Alternatives
The CIE has released a toolbox (DOI: 10.25039/S026.2018.TB) and user guide (DOI: 10.25039/S026.2018.UG) or calculations of quantities specified in CIE S 026/E:2018: CIE System for Metrology of Optical Radiation for ipRGC-Influenced Responses to Light (DOI: 10.25039/S026.2018). The Excel spreadsheet-based toolbox is freely available and is supplementary to the luox platform.
An Excel spreadsheet tool for calculating the CIE Colour Fidelity Index (Rf) is available as a companion to CIE 224:2017 CIE 2017 Colour Fidelity Index for accurate scientific use.
- Calculation definitions
- Acknowledgements
The following individuals tested and provided feedback on an early version of the platform: Paul O'Mahoney, Tos Berendschot, Isabel Schöllhorn, Christine Blume, Katharina Wulff, Kinjiro Amano, Tony Esposito, Minchen Tommy Wei, Suzanne Ftouni, Paula M. Esquivias, Gayline Manalang Jr., Daniel Garside, Joachim Stormly Hansen, and Hao Xie.
- Terms and conditions of website use
What's in these terms?
These terms tell you the rules for using our website https://luox.app/ (our site).
Who we are and how to contact us
Our site operated by the joint research group Chronobiology & Health at the Technical University of Munich and Translational Sensory and Circadian Neuroscience at the Max Planck Institute for Biological Cybernetics (Prof. Dr. Manuel Spitschan). To contact us, please email manuel.spitschan@tum.de.
By using our site you accept these terms
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If you do not agree to these terms, you must not use our site.
We recommend that you print a copy of these terms for future reference.
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We amend these terms from time to time. Every time you wish to use our site, please check these terms to ensure you understand the terms that apply at that time.
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We do not guarantee that our site, or any content on it, will always be available or be uninterrupted. We may suspend or withdraw or restrict the availability of all or any part of our site for business and operational reasons. We will try to give you reasonable notice of any suspension or withdrawal.
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These terms of use, their subject matter and their formation (and any non-contractual disputes or claims) are governed by German law.
- Version information
- Latest tag: wellcome-open-research
- Latest commit SHA: fe38483db011a577d645853be9f8ae371f952297