onlinemeas: determines pion mass and pcac mass from online measured...

In hadron: Analysis Framework for Monte Carlo Simulation Data in Physics

determines pion mass and pcac mass from online measured correlator of the HMC code

Description

determines pion mass and pcac mass from online measured correlator of the HMC code

Usage

onlinemeas(data, t1, t2, stat_range, S = 1.5, pl = FALSE, skip = 0,
  iobs = 1, ind.vec = c(1, 3, 4, 5), mu = 0.1, kappa = 0.125,
  boot.R = 99, boot.l = 10, tsboot.sim = "geom", method = "uwerr",
  fit.routine = "optim", nrep, oldnorm = FALSE)

Arguments

data	data to be fitted to as e.g. the output of readcmicor. Currently only cmicor format is supported.
t1	lower bound for the fitrange in time (t1,t2). Counting starts with 0.
t2	upper bound for the fitrange in time (t1,t2). Counting starts with 0.
stat_range	range of data to be included in the analysis.
S	passed to uwerr, see documentation of uwerr.
pl	logical: if set to TRUE the function produces plots
skip	number of measurements to be discarded at the beginning of the time series. skip has no effect if two or more replica are used, see argument nrep.
iobs	if there are several operators available (local-local, local-smeared, etc.), then this labels these (for cmi format)
ind.vec	index vector indexing the column numbers in cmicor to be used
mu	twisted mass parameter.
kappa	hopping parameter.
boot.R	number of bootstrap samples for bootstrap analysis
boot.l	average block size for blocking analysis with tsboot
tsboot.sim	The type of simulation required to generate the replicate time series. See tsboot for details.
method	the type of error analysis to be used. Can be either “uwerr”, “boot”, “all” or “no”. For “no” (or any other string) no error analysis is performed. This might be helpful for a first impression and also to test different initial values for the fitting parameters. The latter is in particular needed for more than one state in the fit.
fit.routine	The fit routine to be used. Default is “gsl”, which uses the gnu scientific library “gsl_multifit_fdfsolver” solver to minimise the chisquare. All other values lead to the usage of R's optim function. The latter choice might be significantly slower.
nrep	vector (N1, N2, ...) of replica length N1, N2. If missing it is assumed that there is only one ensemble. If there are two or more replica the parameter skip has no effect.
oldnorm	If set to “TRUE”, the old online measurement normalisation of “tmLQCD” prior to version 5.2.0 is used in order to get correct values for the pion decay constant.

Details

The online measurements in the HMC code compute the PP and PA correlation functions summed over spatial x for all t. We analyse these correlators in different ways:

First, only the PP correlator is analysed and fitted by p1*p1*cosh(-m(t-T/2)) for m and p1.

Second, PP and PA correlators are fitted together with three parameters as C_PP = p1*p1*cosh(-m(t-T/2)) and C_PA = p1*p2*cosh(-m(t-T/2))C_PA = p1*p2*cosh(-m(t-T/2)) in a simultaneous fit. m is then the pseudo scalar mass and the pcac mass is determined from

p_1)

Finally, the PCAC mass can also be determined computing

C_PP(t))

(C_PA(t+1)-C_PA(t-1))/(4 C_PP(t))

using the symmetric finite difference operator.

Value

returns an object of class ofit with the following items

fitresult	result from the fit as returned by optim
fitresultpp	Fit result of the PP correlator only
t1	lower bound for the fitrange in time (t1,t2). Counting starts with 0.
t2	upper bound for the fitrange in time (t1,t2). Counting starts with 0.
N	number of measurements found in the data
Time	Time extent found in the data
fitdata	data.frame containing the time values used in the fit, the averaged correlator and its error and the value of Chi for each time value
uwerrresultmps	the result of the time series analysis for the lowest mass as carried out by uwerr
uwerrresultmpcac	the result of the time series analysis for the PCAC mass carried out by uwerr, see details
effmass	effective masses in the pion channel
matrix.size	size of the data matrix, copied from input
boot	object returned by the call to boot if method was set correspodingly. Otherwise NULL.
tsboot	object returned by the call to tsboot if method was set correspodingly. Otherwise NULL.
method	error analysis method as copied from input
fit.routine	fit.routine as copied from input
nrep	nrep as copied from input
dpaopp	data.frame containing the pcac masses computed not with a fit, but with the derivative method for all time values in between t1 and t2

Author(s)

Carsten Urbach, [e-mail]

See Also

readcmicor, uwerr,

hadron documentation built on Sept. 9, 2022, 5:06 p.m.