spc-loess: loess smoothing interpolation for spectra Spectra can be...

In hyperSpec: Work with Hyperspectral Data, i.e. Spectra + Meta Information (Spatial, Time, Concentration, ...)

Description

Applying loess to each of the spectra, an interpolation onto a new wavelength axis is performed. At the same time, the specta are smoothed in order to increase the signal : noise ratio. See loess and loess.control on the parameters that control the amount of smoothing.

Usage

spc.loess(spc, newx, enp.target = nwl(spc)/4, surface = "direct", ...)

Arguments

spc	the hyperSpec object
newx	wavelengh axis to interpolate on
enp.target,surface,...	parameters for loess and loess.control.

Value

a new hyperspec object.

Author(s)

C. Beleites

See Also

loess, loess.control

Examples

plot (flu, col = "darkgray")
plot (spc.loess(flu, seq (420, 470, 5)), add = TRUE, col = "red")

flu [[3, ]] <- NA_real_
smooth <- spc.loess(flu, seq (420, 470, 5))
smooth [[, ]]
plot (smooth, add = TRUE, col = "blue")

Example output

Loading required package: lattice
Loading required package: grid
Loading required package: ggplot2
Package hyperSpec, version 0.99-20180627

To get started, try
   vignette ("hyperspec")
   package?hyperSpec 
   vignette (package = "hyperSpec")

If you use this package please cite it appropriately.
   citation("hyperSpec")
will give you the correct reference.

The project homepage is http://hyperspec.r-forge.r-project.org


Warning message:
In spc.loess(flu, seq(420, 470, 5)) :
  NAs were generated. Probably newx was outside the spectral range covered by spc.
           420       425       430      435      440      445      450      455
[1,]  69.37812  80.30948  91.84728 100.2360 104.5292 104.9064 105.7577 104.8149
[2,] 139.77571 164.01308 186.70646 202.3563 210.6401 213.3784 213.4778 211.8374
[3,]        NA        NA        NA       NA       NA       NA       NA       NA
[4,] 294.90432 342.15512 392.92353 425.2415 440.4607 445.2538 447.5044 440.8911
[5,] 362.00455 427.75670 487.47455 529.7585 550.0944 556.9861 554.9146 548.4495
[6,] 442.89661 519.84822 593.45501 644.1054 669.0614 674.8410 672.3328 666.8127
           460      465       470
[1,]  99.62751  92.9669  84.80506
[2,] 201.97621 187.6462 169.38644
[3,]        NA       NA        NA
[4,] 421.76483 391.7258 354.35753
[5,] 524.96452 487.5104 441.95012
[6,] 639.70144 594.3875 539.25115

hyperSpec documentation built on May 2, 2019, 5:45 p.m.