Function to set by reference the "filter.properties" attribute of an existing filter_spct object.
Usage
setFilterProperties(
x,
filter.properties = NULL,
pass.null = FALSE,
Rfr.constant = NA_real_,
thickness = NA_real_,
attenuation.mode = NA_character_
)
filter_properties(x) <- value
Arguments
- x
a filter_spct object
- filter.properties, value
a list with fields named
"Rfr.constant"
,"thickness"
and"attenuation.mode"
.- pass.null
logical If TRUE, the parameters to the next three parameters will be always ignored, otherwise they will be used to build an object of class
"filter.properties"
when the argument passed to parameterfilter.properties
isNULL
.- Rfr.constant
numeric The value of the reflection factor [/1].
- thickness
numeric The thickness of the material [\(m\)].
- attenuation.mode
character One of
"reflection"
,"absorption"
,"absorption.layer"
,"mixed"
or"stack"
.
Details
Storing filter properties allows inter-conversion between internal
and total transmittance, as well as computation of transmittance for
arbitrary thickness of the material. Whether computations are valid depend
on the homogeneity of the material. The parameter pass.null
makes
it possible to remove the attribute.
Note
This function alters x
itself by reference and in addition
returns x
invisibly. If x
is not a filter_spct
object,
x
is not modified.
The values of attenuation.mode
"reflection"
and
"absorption"
should be used when one of these processes is clearly
the main one; "mixed"
is for cases when they both play a role, i.e.,
when a simple correction using a single value of Rfr
across
wavelengths is not possible; "absorption.layer"
is for cases when a
thin absorbing layer is deposited on the surface of a transparent support
or enclosed between two sheets of glass or other transparent material. If
in doubt, set this to NA
to ensure that computation of spectra for a
different thickness remains disabled.
See also
Other measurement metadata functions:
add_attr2tb()
,
getFilterProperties()
,
getHowMeasured()
,
getInstrDesc()
,
getInstrSettings()
,
getSoluteProperties()
,
getWhatMeasured()
,
getWhenMeasured()
,
getWhereMeasured()
,
get_attributes()
,
isValidInstrDesc()
,
isValidInstrSettings()
,
select_spct_attributes()
,
setHowMeasured()
,
setInstrDesc()
,
setInstrSettings()
,
setSoluteProperties()
,
setWhatMeasured()
,
setWhenMeasured()
,
setWhereMeasured()
,
spct_attr2tb()
,
spct_metadata()
,
subset_attributes()
,
trimInstrDesc()
,
trimInstrSettings()
Examples
my.spct <- polyester.spct
filter_properties(my.spct)
#> Rfr (/1): 0.074, thickness (mm): 0.125, attenuation mode: absorption.
filter_properties(my.spct) <- NULL
filter_properties(my.spct)
#> Rfr (/1): NA, thickness (mm): NA, attenuation mode: NA.
filter_properties(my.spct, return.null = TRUE)
#> NULL
filter_properties(my.spct) <- list(Rfr.constant = 0.01,
thickness = 125e-6,
attenuation.mode = "absorption")
filter_properties(my.spct)
#> Rfr (/1): 0.010, thickness (mm): 0.125, attenuation mode: absorption.