Description Usage Arguments Details Value Author(s) References See Also Examples
View source: R/diffractogram.r
Performs a complete analysis of x-ray diffractogram, i.e. calculation of the baseline and the peak intervals as well as decomposition of the peaks.
1 2 3 | diffractogram(data, tau=2.5,gam=1, scl.factor=1.2, maxwdth=5, intnum=0,
alpha=0.1, maxiter1=500, maxiter=10000, hmax=5, maxsolutions=3,
heterosk=TRUE, baselim=c(0.05,5), dispers=1)
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data |
A diffractogram given as a matrix, where the first column gives the angles of diffraction in 2θ and the second column gives the corresponding photon counts. Angles of diffraction are taken to be equidistant. |
tau |
Value of Parameter tau used in the residual criterion. |
gam |
Factor which is used in the separation between peaks and baseline. |
scl.factor |
Factor which is used in the heteroscedastic residual criterion. |
maxwdth |
Maximum width of the peaks. By default set to 5 degrees. |
intnum |
Vector of numbers of intervals. If |
alpha |
Test level for residual criterion |
maxiter1 |
Number of attempts to fit a model with 1 component |
maxiter |
Number of attempts to fit a model with k > 1 components |
hmax |
Maximum number of components |
maxsolutions |
Number of solutions with k components |
heterosk |
If |
baselim |
Limits for changes in the baseline estimate; first component is given in percent of the baseline height, second in counts per 2θ |
dispers |
Additional dispersion factor; not used if |
diffractogram
first calls baselinefit
with the specified parameters and then pkdecomp
for the output of baselinefit
. For further details, see the corresponding help pages.
Returns a LIST with components
basl |
Output of |
pks |
Output of |
P.L. Davies, M. Meise, T.Mildenberger
P.L. Davies, U. Gather, M. Meise, D. Mergel, T. Mildenberger (2008): "Residual based localization and quantification of peaks in x-ray diffractograms", Annals of Applied Statistics, Vol. 2, No. 3, 861-886.. http://www.statistik.tu-dortmund.de/fileadmin/user_upload/Lehrstuehle/MSind/Publikationen/2008/2008_-_Davies_Gather_Meise_Mergel_Mildenberger_-_Residual_based_localization_and_quantification_of_peaks_in_x-ray_diffractograms.pdf
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 | ## Complete Analysis of a segment from indiumoxide data:
## Identification of baseline and peak as well as decomposition of the peaks
## Plot shows baseline and decomposition of first found peak into two components
set.seed(0)
par(mfrow=c(3,1))
data(indiumoxide)
indox<-indiumoxide[1901:2400,]
sol<-diffractogram(indox,maxsolutions=1,maxiter1=50,maxiter=250)
ind<-c(sol$bas$indlsep[1],sol$bas$indrsep[1])
plot(indox,xlab="",ylab="")
lines(indox[,1],sol$bas$baseline$basisl,col="red")
points(indox[ind[1]:ind[2],],col="blue")
plot(indox[ind[1]:ind[2],1], sol$bas$baseline$peaks[ind[1]:ind[2]],xlab="",ylab="")
lines(indox[ind[1]:ind[2],1],sol$pks[[2]]$fit,col="red")
plot(indox[ind[1]:ind[2],1],sol$pks[[2]]$fitpk[1,],ylim=c(0,1800),type="l",xlab="",ylab="")
lines(indox[ind[1]:ind[2],1],sol$pks[[2]]$fitpk[2,])
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