
	Where results make sense

Topic: Lorentzian function

Related Topics

Cauchy distribution

Doppler profile

Gaussian function

Spectral line

In the News (Sun 15 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	3.3 A minor correction to the Lorentzian theory
		In the previous section, the Lorentzian theory was introduced as a muon spin relaxation theory for dilute spin systems.
		Still, a truly Lorentzian distribution is unphysical, because some fraction of the muons must locate at an infinitesimally small distance from a magnetic ion, in order to realize the diverging second moment of the Lorentzian distribution
		In the traditional Lorentzian theory, the relaxation function in this regime is a square-root exponential function (eq.
	musr.physics.ubc.ca /theses/Kojima/node24.html (410 words)

	The Origin Forum - Define Gaussian-Lorentzian mixture function
		spectroscopy), I need to decompose the original curve into three fitting curves, and I want to define my own fitting method for the peak type, which is mostly used in the XPS analysis software, its a mixture of a Gaussian and a Lorentzian, and I can change the ratio of the two in the method.
		Posted - 10/31/2006 : 11:22:49 PM The built-in PsdVoight1 or PsdVoight2 function is probably what you want.
		in PsdViogt1, Gaussian and Lorentzian have the same width
	www.originlab.com /forum/topic.asp?TOPIC_ID=5254 (191 words)

	Mesh Toolbox : ICP2
		The Lorentzian weighting function is designed to reduce the influence of outliers on the algorithm.
		Assuming errors are distributed according to the Lorentzian leads to a weighed least squares minimization where the weights are the Lorentzian of the error.
		The sigmoid weighting function has a similar shape to the Lorentzian but has the advantage that its parameters can be adjusted to approximate a step-edge threshold as well.
	www.cs.cmu.edu /~vmr/software/meshtoolbox/executables/ICP2.html (1318 words)

	Ahelp (contextual) - CIAO 3.4
		Module functions to retrieve filenames associated with a dataset.
		Joint-mode models define the function argument, on which a model expression is evaluated, to be a particular data axis.
		Nested models define the function argument on which a model expression is evaluated to be another model expression.
	asc.harvard.edu /ciao/ahelp/index_context.html (4350 words)

	NationMaster - Encyclopedia: Lorentzian function
		When normalize is yes, the normalization value for the function will be determined empirically by applying the function to the center of a dummy image of the same size as the output file and summing the pixel values.
		When applied at a source's coordinates, the model profile function is scaled by the source intensity, the initial (overall) scale, and (optionally) the function normalization factor.
		Functions are applied to every image pixel for each source, even far from the source center where the model value is effectively zero.
	www.nationmaster.com /encyclopedia/Lorentzian-function (201 words)

	IRAF Help page for "imsmooth" (V2.10.4p2)
		The amount of wrap-around is determined by the radius of the smoothing function and the magnitude of the difference between the data on one edge and that on the opposite edge.
		The hipass function is a tophat in k space with radius in pixels.
		The lopass function is an inverse tophat (circularly symmetrical hole) in kspace with radius in pixels.
	ecf.hq.eso.org /scripts/irafhelp?imsmooth (1910 words)

	Cauchy distribution - Biocrawler (Site not responding. Last check: )
		Since it is a distribution function, it integrates to unity:
		The Cauchy distribution is often cited as an example of a distribution which has no mean, variance or higher moments defined, although its mode and median are well defined and are both equal to x
		When U and V are two independent normally distributed random variables with expected value 0 and variance 1, then the ratio U/V has the standard Cauchy distribution.
	www.biocrawler.com /encyclopedia/Lorentzian (634 words)

	Cauchy distribution
		The Cauchy distribution is a probability distribution with probability density function
		The Cauchy distribution is often cited as an example of a distribution which has no mean, variance or higher moments defined, although its mode and median are well defined and both zero.
		This example serves to show that the hypothesis of finite variance in the central limit theorem cannot be dropped (although it can be replaced with other, in some cases weaker, assumptions).
	www.abacci.com /wikipedia/topic.aspx?cur_title=Lorentzian_function (276 words)

	NationMaster - Encyclopedia: Metric tensor (general relativity)
		A manifold M equipped with such a metric is called a Lorentzian manifold.
		In mathematics, a manifold M is a type of space, characterised in one of two equivalent ways: near every point of the space, we have a coordinate system; or near every point, the environment is like that in Euclidean space of a given dimension.
		In mathematics, the exterior derivative operator of differential topology, extends the concept of the differential of a function to differential forms of higher degree.
	www.nationmaster.com /encyclopedia/Metric-tensor-%28general-relativity%29 (2318 words)

	the `octopus' 1.4 manual (Site not responding. Last check: )
		A damping function may be applied to the input fuction before processing the Fourier transform.
		This function may be an exponential, a third order polynomial (fit to be one at t=0, and also its derivative, and null at t=T), or a gaussian: "exp" or "pol" or "gau".
		It amounts to applying a convolution of the signal in Fourier space, either with a Lorentzian function (for the exponential), with a Gaussian function (for the Gaussian), or with some other function (in the case of the third order polynomial.
	www.tddft.org /programs/octopus/download/1.4/octopus.html/SpecDampMode.html (147 words)

	GUI Programming with PyQT
		NumPy is useful for everybody who analyzes data with the help of a spreadsheet program like Microsoft Excel—it is not just for mathematicians and scientists who crunch lots of data.
		All the functionality of NumPy can be obtained in pure Python, but NumPy gives you speed and elegance.
		I wrote the function lorentzian(x) assuming that x is Python float.
	www.commandprompt.com /community/pyqt/a8743 (815 words)

	[No title]
		Convolve an image with a circular Lorentzian function of sigma 2.0, and size 4.0 sigma using nearest neighbor boundary extension.
		Convolve an image with an elliptical Lorentzian function whose sigma in the major and minor axis direction is 2.0 and 1.5 respectively, and whose position angle is 45 degrees, using wrap around boundary extension.
		Convolve an image in the 3rd extension with a circular Lorentzian function of sigma 2.0, and size 4.0 sigma using nearest neighbor boundary extension and store the resulting image in the primary array.
	starchild.gsfc.nasa.gov /lheasoft/ftools/fhelp/florentz.txt (896 words)

	Bragg Institute - Scientific highlights - Evaluation of sub-surface microstructure in sintered ceramic materials (Site not responding. Last check: )
		The effect of sintering on both the XRD and ND Gaussian and Lorentzian peak breadths is shown in Figure 3.
		A slight increase in the ND Gaussian breadth is also observed, whereas the ND Lorentzian breadth vanishes for the 1450°C-2h and 1600°C-6h data sets.
		Effects of sintering on the FWHM Gaussian and Lorentzian component values for the 422 reflection of the MgO specimens using ND and XRD data.
	www.ansto.gov.au /ansto/bragg/highlights/2002_04_oconnor.html (970 words)

	8.1 Fitting 1d data sets
		The next function (equation 8.2) is a sum of N Gaussians and a linear background defined by the first two parameters p
		The Lorentzian theory function (equation 8.3) is defined by a similar set of parameters.
		Currently both function types can not be used in combination except as user defined theory function as described in section 8.3.
	www.uni-wuerzburg.de /mineralogie/crystal/discus/kupman/node47.html (1068 words)

	Lorentzian function
		The -corrected dynamical Lorentzian function is well approximated by a `stretched' exponential function, ; in Fig.
		This function returns a Lorentzian lineshape with centre x0 and full width at half height fwhm over the abscissa values defined in the vector x.
		The integral over the Lorentzian function and the principal value integral can be performed analytically resulting in monotonic functions and.
	www.logicjungle.com /wiki/Lorentzian_function (308 words)

	PISAPEAK - Transforms the PISAFIND parameterisations so that the variables are intensity invariant
		Using the PISA profiling function it then transforms certain of the variables into values which are intensity invariant for a radial stellar profile.
		The mixture coefficient, as a fraction of the Gaussian peak, of a Lorentzian function used to model the wings of the stellar profile.
		At each point in the analytical profile the Lorentzian function is added to the Gaussian/exponential core scaled by the mixture coefficient.
	www.strw.leidenuniv.nl /docs/starlink/sun109.htx/node40.html (550 words)

	data processing
		In VNMR, a Gaussian function is defined by the two parameters, gf (its exponent, in the following example, it has been set to 1/2 the acquisition time), and gfs(the position of the maximum, in the following example, this has been set to 0, corresponding to the beginning of the FID).
		This can be done by, for example, shifting the Gaussian apodization function (which simply involves setting gfs to the desired portion of the FID to be amplified).
		The weighting function is composed of a Gaussian (centered at time=0) and a shifted sinebell function.
	bouman.chem.georgetown.edu /nmr/nuts/datproc.htm (640 words)

	The Ontological Interpretation of the Wave Function of the Universe
		Given this denial that his remarks are to be read as suggesting an ontological interpretation of the wave function of the universe, we may allow that Isham cannot properly be charged with a contradiction or lack of specificity in an ontological interpretation of the equation.
		Since our Lorentzian and Euclidean metrics are present only when the WKB solution is an approximation to the Wheeler-DeWitt equation, we do not have a Lorentzian or Euclidean metric in the physical region that corresponds to this "matching" region in mathematical space.
		A decoherence functional is used to assign the probabilities, and the "branches" are analyzed in terms of decohering sets of alternative histories.
	www.qsmithwmu.com /the_ontological_interpretation_of_the_wave_function_of_the_universe.htm (9089 words)

	Window functions
		Before applying a window function or doing an FT, the FID may need to be corrected for any offset from zero.
		A quick way to see the shape of a chosen function is to open the FID to which it will be applied and execute the 21 command.
		This is a gaussian function for 2D data, in which the center of the gaussian is shifted based on the slice number.
	www.acornnmr.com /NutsHelp/apodization.html (1112 words)

	1810s . 1790s . 1840s . 1818 . 20th century
		The reasons for this broadening are several: Natural broadening: The Uncertainty principle relates the life of an excited state with the precision of the energy, so the same excited level will have slightly different energies in different atoms.
		This broadening effect is described by a Lorentzian function Lorentzian profile.
		Resonance broadening: This broadening effect is described by a Lorentzian function Lorentzian profile.
	www.uk.knowledge-info.org /1810s-UK-4282442-iq (186 words)

	Core Library
		The core library gathers all the basic constants and mathematical functions needed to construct complex spectroscopic models.
		Peak functions such as the gaussian and lorentzian functions, several absorption profiles corresponding to microscopic mechanisms of absorption, a few classic base lines, sequences and other miscellaneous functions are also present in this library.
		The sgl token represents a mixing of gaussian and lorentzian functions.
	crmht.cnrs-orleans.fr /POT/software/osml-core.html (1809 words)

	Voigt profile - Definition, explanation
		The Doppler profile is essentially a normal distribution and a Lorentzian profile is essentially a Cauchy distribution.
		The Lorentzian profile has no moments (other than the zeroth) and so the moment-generating function for the Cauchy distribution is not defined.
		It follows that the Voigt profile will not have a moment-generating functon either, but the characteristic function for the Cauchy distribution is well defined, as is the characteristic function for the normal distribution.
	www.calsky.com /lexikon/en/txt/v/vo/voigt_profile.php (450 words)

	XPS-STD Pilot Study
		Use of the Gaussian-Lorentzian function fitted to spectra resulted in smaller biases than the use of a Gaussian function alone.
		BE of smaller component function = BE of larger component function + 0.68 eV.
		Function used with two Gaussian components and one linear component (for background).
	www.cstl.nist.gov /div837/837.01/outputs/standards/STData/pilot_study.html (1175 words)

	Tektronix MBD: Applications > Signals and Measurements: Read Channel Signal
		This is the voltage response at the output of the read head in response to an isolated transition on the media.
		Equation 1 shows the basic Lorentzian function, where t is time and x is a parameter which controls the pulse width.
		Figure 1 plots the Lorentzian function for a bit interval of T=20 ns and a PW50/T ratio of 1.2.
	www.tek.com /Measurement/App_Notes/awg2041/read.html (457 words)

	Curve fitting downloads - DataFit, Advanced Grapher, FindGraph
		Graphs Cartesian, polar and parametric functions, graphs of tables, implicit functions, inequalities and slope fields.
		Lorentzian, Sine, Exponential and Power series are available models to match your data.
		NLREG fits a mathematical function whose form you specify to a set of data values.
	www.vicman.net /lib/curve-fitting.htm (742 words)

	Interactive Peak Fitter
		It controls the extra shape factor of the Pearson (a value of 1.0 gives a Lorentzian shape, a value of 2.0 gives a shape rouighly half-way between a Lorentzian and a Gaussian, and a larger values give a nearly Gaussian shape) and it also controls the time constant of the exponentionally-broadened gaussian.
		To add a new peak shape to the five initial shapes, you must have a function for that peak shape, similar to gaussian.m, that takes as arguments a vector of x-values, a peak-center value, and a peak width, and returns a vector of that function evaluated at each value of x.
		Note: If your function requires three adjustable arguments rather than two, you can assign one to the Extra slider, as is done here for the exponentially-broadened Gaussian and Pearson-type shape.
	www.wam.umd.edu /~toh/spectrum/InteractivePeakFitter.htm (1614 words)

	Projection of World Population
		A generalized version of the inverse tangent function is devised and found to yield an excellent fit to the World population data.
		The functions that have been used to fit the World population data are listed here for the edification of those readers who are mathematically inclined.
		The generalized inverse tangent function is even more realistic, because it allows for an asymmetry; and it yields overwhelmingly the best fit of the four functions to the World data.
	arts.bev.net /roperldavid/WorldPop.htm (3738 words)

	a curve fitting program: Sine, Power, Exponential, + Lorentzian series
		A Lorentzian series is recommended for real data especially for multiple peaked data.
		All features of the waveforms are automatically scaled to fit the image (or selection of course) so you will not have to reconfigure an entire wave should you decide to change the image size.
		The Test Tone Generator (TTG) turns the PC into a function generator for testing or demonstration, sound tuning, education or for sound effects.
	www.softwaremarketingresource.com /sine.htm (515 words)

	Gaussian fits to the MEG LSF
		The effects of fitting a Gaussian function to a line spread function which is more complex, a Gaussian core with Lorentzian conponent for the wings, can result in a narrower Gaussian than would be obtained by using the more complete Gaussian plus Lorentzian function.
		To demonstrate this effect a simulation was generated using a delta function convolved with the RMF for the first order MEG which has both the Gaussian and Lorentzian component.
		This function was then fit with a Gaussian that was not convolved with the RMF so that the wings would not appear.
	space.mit.edu /ASC/analysis/lsf_fits/node3.html (149 words)

	EECS 232 Fall 2005
		For power density in the laser cavity P (in W/cm^2), reflectivity R ~ 0, the output power density in air is P*(1-R) ~ P. Photon flux is simply P/(hv), and photon energy hv is the same for photons in and outside laser cavity, so the photon fluxes are almos the same.
		The corresponding width of the Lorentzian lineshape is ~ 13 meV.
		In quantum box problem, such as the one in HW#2, you need to use Lorentzian lineshape function to get a realistic absorption coefficient (otherwise, it becames infinity).
	www.eecs.berkeley.edu /~wu/ee232/Virtual_OH.htm (349 words)

Try your search on: Qwika (all wikis)