pkdecompint {diffractometry} | R Documentation |
Decomposition of peaks in an interval of the diffractogram
pkdecompint(baslfit, intnum, k, thresh=0, alpha=0.1, heterosk=TRUE, maxiter=10000, dispers=1, baselim=c(0.05,5))
baslfit |
Output of baslfit |
intnum |
Number of interval |
k |
Number of peak components to fit |
thresh |
Threshold for residual criterion |
alpha |
Test level for residual criterion |
heterosk |
If TRUE , the estimate of noise level given in baslfit is used (default); otherwise noise level is taken to be proportional to signal height |
maxiter |
Number of attempts to fit a model with k components |
dispers |
Additional dispersion factor; not used if heterosk==T |
baselim |
Limits for changes in the baseline estimate; first component is given in percent of the baseline height, second in counts/2theta |
Returns a LIST with components
intnr |
Number of interval |
x |
values of 2theta |
y |
the diffractogram with baseline removed |
fit |
the resulting fit, evaluated at all points of x |
fitpk |
a matrix with num.ker rows that contain fits of the individual peak components |
basl |
the basline estimate as given in baslfit |
baslchg |
chnage of baseline estimate |
rss |
residual sum of squares, standardized by noise level estimate |
num.ker |
number of peak components |
par |
parameter vector as given in section 8 of Davies et al. (2008) |
parbl |
intercept and slope of the baseline change |
parpks |
physical characteristics of the peaks |
accept |
is the fit accepted by the residual criterion |
alpha |
test level for residual criterion |
thresh |
threshold used in residual criterion |
T. Mildenberger; Algorithm for residual criterion by T. Bernholt and T. Hofmeister
P.L. Davies, U. Gather, M. Meise, D. Mergel, T. Mildenberger (2008): "Residual based localization and quantification of peaks in x-ray diffractograms", to appear in the Annals of Applied Statistics. http://arxiv.org/abs/0711.3687
T. Bernholt and T. Hofmeister (2006): "An algorithm for a generalized maximum subsequence problem", in: J. Correa, A. Hevia, M. Kiwi (editors), "Latin 2006: Theoretical Informatics", volume 3887 of Lecture notes in Computer Science, pages 178-189, Berlin, Heidelberg. Springer Verlag
diffractogram
, baselinefit
, pkdecomp
## Decomposition of data in peak interval into two components par(mfrow=c(2,1)) data(indiumoxide) indox<-indiumoxide[1901:2400,] base<-baselinefit(indox) ind<-c(base$indlsep[1],base$indrsep[1]) plot(indox[ind[1]:ind[2],1], base$baseline$peaks[ind[1]:ind[2]],xlab="",ylab="") pks<-pkdecompint(base,intnum=1,k=2) lines(indox[ind[1]:ind[2],1],pks$fit,col="red") plot(indox[ind[1]:ind[2],1],pks$fitpk[1,],ylim=c(0,1800),type="l",xlab="",ylab="") lines(indox[ind[1]:ind[2],1],pks$fitpk[2,])