Getting Started

library(SpectralUnmix)

Simulated example

demo <- simulate_ifu_cube(nx = 16, ny = 16, n_wave = 100)
fit <- spectral_unmix(
  demo$matrix,
  k = 3,
  lambda_smooth = 0.02,
  niter = 300,
  lr = 0.03
)

Standard interface

print(fit)
summary(fit)
basis(fit)
coef(fit)

Plots

plot(fit, type = "spectra", wavelength = demo$wavelength)
plot(fit, type = "maps", nx = demo$nx, ny = demo$ny)
plot(fit, type = "loss")
plot_reconstruction(fit, demo$matrix, n = 4, wavelength = demo$wavelength)

Example figures

Component spectra:

Component maps:

Observed versus reconstructed spectra:

What the outputs mean

fit$spatial contains one abundance weight per spaxel and per component.
fit$spectra contains the recovered component spectra.
fit$reconstruction is the model approximation A %*% S.
fitted(fit, nx, ny) and predict(fit, type = "cube", nx, ny) reshape that reconstruction back into a cube.
residuals(fit, x = ...) returns data minus reconstruction.

Real library example

real_demo <- coelho_demo_spectra()
dim(real_demo$matrix)

[1]    4 2250

real_demo$metadata

           id                         file  teff logg feh
1  cool_giant t03000_g-0.5_p00p00_sed.fits  3000 -0.5 0.0
2 solar_dwarf t05750_g+4.5_p00p04_sed.fits  5750  4.5 0.0
3      a_star t09000_g+4.5_p00p00_sed.fits  9000  4.5 0.0
4    hot_star t18000_g+4.5_p02p00_sed.fits 18000  4.5 0.2

fit_real <- spectral_unmix(
  real_demo$matrix,
  k = 3,
  lambda_smooth = 0.001,
  niter = 400,
  lr = 0.03
)

plot(fit_real, type = "spectra", wavelength = real_demo$wavelength)
plot_reconstruction(
  fit_real,
  real_demo$matrix,
  n = 4,
  wavelength = real_demo$wavelength
)

Static reconstruction view for the Coelho demo sample:

Stellar library compression

stellar_lib <- coelho_stellar_subset()
dim(stellar_lib$matrix)

[1]  100 2250

table(stellar_lib$metadata$type)


  a_f_star cool_dwarf cool_giant   hot_star solar_like 
        20         20         20         20         20

fit_lib <- spectral_unmix(
  stellar_lib$matrix,
  k = 5,
  lambda_smooth = 0.001,
  niter = 500,
  lr = 0.03
)

plot(fit_lib, type = "spectra", wavelength = stellar_lib$wavelength)
plot_reconstruction(
  fit_lib,
  stellar_lib$matrix,
  n = 6,
  wavelength = stellar_lib$wavelength
)