Method to compute the "parallel" variance of values across members of a collections of spectra or of a spectral object containing multiple spectra in long form.
Usage
s_var(x, na.rm, ...)
# Default S3 method
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'generic_spct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'filter_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'source_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'response_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'reflector_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'calibration_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'cps_mspct'
s_var(x, na.rm = FALSE, ...)
# S3 method for class 'raw_mspct'
s_var(x, na.rm = FALSE, ...)
Value
If x
is a collection spectral of objects, such as a
"filter_mspct"
object, the returned object is of same class as the
members of the collection, such as "filter_spct"
, containing the
summary spectrum, with variables with names tagged for summaries other
than mean or median.
Details
Method specializations compute the variance at each wavelength
across a group of spectra stored in an object of one of the classes defined
in package 'photobiology'. Omission of NAs is done separately at each
wavelength. Interpolation is not applied, so all spectra in x
must
share the same set of wavelengths. An error is triggered if this condition
is nor fulfilled.
Methods (by class)
s_var(default)
:s_var(generic_spct)
:s_var(filter_mspct)
:s_var(source_mspct)
:s_var(response_mspct)
:s_var(reflector_mspct)
:s_var(calibration_mspct)
:s_var(cps_mspct)
:s_var(raw_mspct)
:
Note
Objects of classes raw_spct
and cps_spct
can contain data
from multiple scans in multiple variables or "columns". The methods accept
as arguments objects of these classes only if spectra contain data for a
single spectrometer scan. In the case of cps_spct
objects, a single
column can also contain data from multiple scans spliced into a single
variable.
Examples
s_var(sun_evening.mspct)
#> Object: generic_spct [1,593 x 2]
#> Wavelength range 290-1000 nm, step 0.34-0.47 nm
#> Label: Variance for 5 source_spct objects.
#> Variables:
#>
#> --
#> # A tibble: 1,593 × 2
#> w.length s.e.irrad.var
#> <dbl> <dbl>
#> 1 290 0
#> 2 290. 0
#> 3 291. 0
#> 4 291. 0
#> 5 292. 0
#> 6 292. 0
#> 7 293. 0
#> 8 293. 0
#> 9 294. 0
#> 10 294. 0
#> # ℹ 1,583 more rows