Candela was chosen so that the new definition would precisely match the old definition. Although the candela is now defined in terms of the second (an SI base unit) and the watt (a derived SI unit), the candela remains a base unit of the SI system, by definition. If a source emits a known luminous intensity "I" (in candelas) in a well-defined cone, the total luminous flux "Φ" in lumens is given by where "A" is the "radiation angle" of the lamp—the full vertex angle of the emission cone. For example, a lamp that emits 590 cd with a radiation angle
Probability measure of a system S assuming state A is p" the geometry of the system does not always lead to the definition of a probability measure under congruence, although it may do so in the case of systems with just one degree of freedom. Probability measures are also used in mathematical biology. For instance, in comparative sequence analysis a probability measure may be defined for the likelihood that a variant may be permissible for an amino acid in a sequence. Probability measure In mathematics, a probability measure is a real-valued function defined on a set of events in a probability space