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README.md

@@ -17,3 +17,11 @@ This will link the files into your environment instead of copying them. If you a
 
 ## qutil.matlab
 In this module there are functions that are helpful for reading `.mat` files, especially those created with special measure. If you simply want to open a random `.mat` file you can use `hdf5storage.loadmat`.
+
+## qutil.linalg
+This module provides several handy linear algebra functions. While some are implemented elsewhere, the implementation here is typically speedier for large arrays. For example, `pauli_expm` exploits the fact that a matrix exponential of Pauli matrices can be written as a cosine times the identity matrix plus a sine times the Paulis to speed up the calculation. 
+
+For an overview of the included functions, see the module docstring.
+
+## qutil.qi
+In this module there are some quantities and functions related to quantum information, like the Pauli matrices in different data types.

qutil/const.py

+"""
+This module defines constants, mostly wrapped from scipy. Many constants are in
+the top-level namespace. Many more are in the dictionary ``physical_constants``
+that can be searched using :meth:`find` and accessed using :meth`value`.
+
+On top of the scipy constants, the following shorthands are defined:
+
+e2 : :math:`e^2`
+pi2 : :math:`\pi/2`
+pi4 : :math`\pi/4`
+tpi : :math`2\pi`
+fpi : :math`4\pi`
+
+Functions
+---------
+:meth:`convert_temperature` :
+    Convert temperature between different scales
+:meth:`find` :
+    Find constants in the ``physical_constants`` dictionary matching a string
+:meth:`lambda2nu` :
+    Convert wavelength to frequency
+:meth:`nu2lambda` :
+    Convert frequency to wavelength
+:meth:`unit` :
+    Get the unit of a constant in the ``physical_constants`` dictionary.
+:meth:`value` :
+    Get the value of a constant in the ``physical_constants`` dictionary.
+:meth:`precision` :
+    Get the precision of a constant in the ``physical_constants`` dictionary.
+"""
+
+from scipy.constants import (
+    Avogadro,
+    Boltzmann,
+    Btu,
+    Btu_IT,
+    Btu_th,
+    G,
+    Julian_year,
+    N_A,
+    Planck,
+    R,
+    Rydberg,
+    Stefan_Boltzmann,
+    Wien,
+    acre,
+    alpha,
+    angstrom,
+    arcmin,
+    arcminute,
+    arcsec,
+    arcsecond,
+    astronomical_unit,
+    atm,
+    atmosphere,
+    atomic_mass,
+    atto,
+    au,
+    bar,
+    barrel,
+    bbl,
+    blob,
+    c,
+    calorie,
+    calorie_IT,
+    calorie_th,
+    carat,
+    centi,
+    convert_temperature,
+    day,
+    deci,
+    degree,
+    degree_Fahrenheit,
+    deka,
+    dyn,
+    dyne,
+    e,
+    eV,
+    electron_mass,
+    electron_volt,
+    elementary_charge,
+    epsilon_0,
+    erg,
+    exa,
+    exbi,
+    femto,
+    fermi,
+    find,
+    fine_structure,
+    fluid_ounce,
+    fluid_ounce_US,
+    fluid_ounce_imp,
+    foot,
+    g,
+    gallon,
+    gallon_US,
+    gallon_imp,
+    gas_constant,
+    gibi,
+    giga,
+    golden,
+    golden_ratio,
+    grain,
+    gram,
+    gravitational_constant,
+    h,
+    hbar,
+    hectare,
+    hecto,
+    horsepower,
+    hour,
+    hp,
+    inch,
+    k,
+    kgf,
+    kibi,
+    kilo,
+    kilogram_force,
+    kmh,
+    knot,
+    lambda2nu,
+    lb,
+    lbf,
+    light_year,
+    liter,
+    litre,
+    long_ton,
+    m_e,
+    m_n,
+    m_p,
+    m_u,
+    mach,
+    mebi,
+    mega,
+    metric_ton,
+    micro,
+    micron,
+    mil,
+    mile,
+    milli,
+    minute,
+    mmHg,
+    mph,
+    mu_0,
+    nano,
+    nautical_mile,
+    neutron_mass,
+    nu2lambda,
+    ounce,
+    oz,
+    parsec,
+    pebi,
+    peta,
+    physical_constants,
+    pi,
+    pico,
+    point,
+    pound,
+    pound_force,
+    precision,
+    proton_mass,
+    psi,
+    pt,
+    short_ton,
+    sigma,
+    slinch,
+    slug,
+    speed_of_light,
+    speed_of_sound,
+    stone,
+    survey_foot,
+    survey_mile,
+    tebi,
+    tera,
+    ton_TNT,
+    torr,
+    troy_ounce,
+    troy_pound,
+    u,
+    unit,
+    value,
+    week,
+    yard,
+    year,
+    yobi,
+    yotta,
+    zebi,
+    zepto,
+    zero_Celsius,
+    zetta
+)
+
+e2 = e**2
+pi2 = pi/2
+pi4 = pi/4
+tpi = pi*2
+fpi = pi*4