Subsetting hyperspectral object

Subsetting of hyperspectral object may be done with specifying spectral range or spectra indices, but also with subset function. Combining this with grepl function allows for selecting groups with particular names.

a3
hyperSpec object
   22 spectra
   3 data columns
   3101 data points / spectrum
wavelength:  [numeric] 700 701 ... 3800
data:  (22 rows x 3 columns)
   1. files:  [factor] DP_Br_n_1_20170717_1702_0.txt DP_Br_n_1_20170717_1705_0.txt ... DP_I_n_4_20170717_1623_0.txt
   2. group:  [factor] Br_n_1 Br_n_1 ... I_n_4_
   3. spc:  [matrix3101] -0.0010941127 -0.0009799145 ... 0.01204381
  
#partial spectral range
a3range<-a3[,,1000~1500]
a3range
hyperSpec object
   22 spectra
   3 data columns
   501 data points / spectrum
wavelength:  [numeric] 1000 1001 ... 1500
data:  (22 rows x 3 columns)
   1. files:  [factor] DP_Br_n_1_20170717_1702_0.txt DP_Br_n_1_20170717_1705_0.txt ... DP_I_n_4_20170717_1623_0.txt
   2. group:  [factor] Br_n_1 Br_n_1 ... I_n_4_
   3. spc:  [matrix501] 0.05538213 0.04516893 ... 0.1254986

# some spectra
a3some<-a3[2:19,,]
a3some
hyperSpec object
   18 spectra
   3 data columns
   3101 data points / spectrum
wavelength:  [numeric] 700 701 ... 3800
data:  (18 rows x 3 columns)
   1. files:  [factor] DP_Br_n_1_20170717_1705_0.txt DP_Br_n_1_20170717_1707_0.txt ... DP_I_n_3_20170717_1601_0.txt
   2. group:  [factor] Br_n_1 Br_n_1 ... I_n_3_
   3. spc:  [matrix3101] -0.0009799145 -0.0035743618 ... 0.0122932

# some groups (names in vector select01)
select01<-c("Br_n_1","Cl_n_1","I_n_1_")
a3groups01<-subset(a3, group %in% select01)
a3groups01
hyperSpec object
   13 spectra
   3 data columns
   3101 data points / spectrum
wavelength:  [numeric] 700 701 ... 3800
data:  (13 rows x 3 columns)
   1. files:  [factor] DP_Br_n_1_20170717_1702_0.txt DP_Br_n_1_20170717_1705_0.txt ... DP_I_n_1_20170717_1505_0.txt
   2. group:  [factor] Br_n_1 Br_n_1 ... I_n_1_
   3. spc:  [matrix3101] -0.0010941127 -0.0009799145 ... 0.02612447

# some groups (group name include I)
p1 <- "I"
a3groups02<-subset(a3, grepl(p1, group))
# or
a3groups02<-subset(a3, grepl("I", group))
a3groups02
hyperSpec object
   12 spectra
   3 data columns
   3101 data points / spectrum
wavelength:  [numeric] 700 701 ... 3800
data:  (12 rows x 3 columns)
   1. files:  [factor] DP_I_n_1_20170717_1456_0.txt DP_I_n_1_20170717_1504_0.txt ... DP_I_n_4_20170717_1623_0.txt
   2. group:  [factor] I_n_1_ I_n_1_ ... I_n_4_
   3. spc:  [matrix3101] -0.002799757 -0.002894319 ... 0.012043