Welcome, guest | Sign In | My Account | Store | Cart

Notice! PyPM is being replaced with the ActiveState Platform, which enhances PyPM’s build and deploy capabilities. Create your free Platform account to download ActivePython or customize Python with the packages you require and get automatic updates.

pypm install ref-index

How to install ref_index

  1. Download and install ActivePython
  2. Open Command Prompt
  3. Type pypm install ref-index
 Python 2.7Python 3.2Python 3.3
Windows (32-bit)
1.0 Available View build log
Windows (64-bit)
1.0 Available View build log
Mac OS X (10.5+)
1.0 Available View build log
Linux (32-bit)
1.0 Available View build log
Linux (64-bit)
1.0 Available View build log
Lastest release
version 1.0 on Oct 12th, 2011

Code for calculating refractive index of air, under varying atmospheric conditions, is provided in this module. Functions for conversion of wave length of light in vacuum to that in air, and vice-versa are also defined.

The code is based on the documentation for the NIST online refractive index of air calculator.


Refractive index can be calculated using two different equations: one due to Edlén and another due to Ciddor.

>>> ref_index.ciddor(wave=633.0, t=20, p=101325, rh=20)
>>> ref_index.edlen(wave=633.0, t=20, p=101325, rh=20)
>>> ref_index.edlen(wave=633.0, t=20, p=101325, rh=80)
>>> ref_index.ciddor(wave=633.0, t=20, p=101325, rh=80)
>>> ref_index.edlen(wave=633.0, t=60, p=101325, rh=80)
>>> ref_index.ciddor(wave=633.0, t=60, p=101325, rh=80)

Conversion of wave length of light in vacuum to that in air, and vice-versa. Both of these functions use the Ciddor equation, as implemented in ciddor_ri() and ciddor().

>>> ref_index.vac2air(633.0)
>>> ref_index.air2vac(632.82500476826874)

>>> ref_index.vac2air(np.array([633.0, 550.0, 400.0]))
array([ 632.82500477,  549.84723175,  399.88692724])
>>> x = ref_index.vac2air(np.array([633.0, 550.0, 400.0]))
>>> ref_index.air2vac(x)
array([ 633.0000014 ,  550.00000164,  400.00000243])

Note that the reversibility of air2vac() is ~1e-5nm.

Default temperature is 15∘C, pressure is 101325Pa, relative humidity is 0, and CO2 concentration is 450µmole/mole. All these can be changed.

>>> ref_index.vac2air(633.0, t=20, p=100000.0, rh=50)
>>> ref_index.air2vac(632.83051710791892, t=20, p=100000.0, rh=50)

For more details please see the docstring for the module. Detailed description of the equations can be found in the NIST documentation.


The module can be installed using pip and easy_install.

$ pip install ref_index


$ easy_install ref_index


All equations used in this module come from the documentation for the NIST online refractive index calculator, written by Jack A. Stone and Jay H. Zimmerman.

Please send comments and suggestions to the email id prasanthhn in the gmail.com domain.

Subscribe to package updates

Last updated Oct 12th, 2011

Download Stats

Last month:4

What does the lock icon mean?

Builds marked with a lock icon are only available via PyPM to users with a current ActivePython Business Edition subscription.

Need custom builds or support?

ActivePython Enterprise Edition guarantees priority access to technical support, indemnification, expert consulting and quality-assured language builds.

Plan on re-distributing ActivePython?

Get re-distribution rights and eliminate legal risks with ActivePython OEM Edition.