OPI (version 2.10.1)

dbTocd: Convert dB to cd/\(\mbox{m}^2\)

Description

Given a value in dB, return the cd/\(\mbox{m}^2\) equivalent. Default is to use HFA units, so maximum stimulus is 10000 apostilbs

Usage

dbTocd(db, maxStim = 10000/pi)
cdTodb(cd, maxStim = 10000/pi)

Arguments

db

Value to convert to cd

maxStim

Stimulus value for 0dB in cd/\(\mbox{m}^2\)

cd

Value to convert to dB in cd/\(\mbox{m}^2\)

Value

dbTocd returns cd/\(\mbox{m}^2\) value

cdTodb returns a dB value.

Examples

# NOT RUN {
# decibels to candela
cd <- dbTocd(0)   # 10000/pi
cd <- dbTocd(10)  # 1000/pi
cd <- dbTocd(20)  # 100/pi
cd <- dbTocd(30)  # 10/pi
cd <- dbTocd(40)  # 1/pi
# candela to decibels
dB <- cdTodb(10000/pi)  # 0 dB
dB <- cdTodb(1000/pi)   # 10 dB
dB <- cdTodb(100/pi)    # 20 dB
dB <- cdTodb(10/pi)     # 30 dB
dB <- cdTodb(1/pi)      # 40 dB
dB <- cdTodb(0.1/pi)    # 50 dB
# }