A matrix is normal if A AH = AH A, where AH is the conjugate transpose of A For real A this is equivalent to A AT = AT A Note that a complex matrix is normal if and only if there is a unitary Q such that QH A Q is diagonal
According to an established norm, rule, or principle; conformed to a type, standard, or regular form; performing the proper functions; not abnormal; regular; natural; analogical
This is a slippery, dangerous term, because what's normal to one person at one time is abnormal to another person, another time The use of "normal" to describe brake reach is a very common source of confusion and trouble
The long-term average value of a meteorological element for a certain area For example, "temperatures are normal for this time of year " Usually averaged over 30 years
Something that is normal is usual and ordinary, and is what people expect. He has occasional injections to maintain his good health but otherwise he lives a normal life The two countries resumed normal diplomatic relations Some of the shops were closed but that's quite normal for a Thursday afternoon Life in Israel will continue as normal