Search results
Results from the WOW.Com Content Network
In statistics, the phi coefficient (or mean square contingency coefficient and denoted by φ or r φ) is a measure of association for two binary variables.. In machine learning, it is known as the Matthews correlation coefficient (MCC) and used as a measure of the quality of binary (two-class) classifications, introduced by biochemist Brian W. Matthews in 1975.
Integrated information theory (IIT) the symbol of which is φ is a mathematical theory of consciousness developed under the lead of the neuroscientist Giulio Tononi Standard normal distribution , Φ ( x ) {\displaystyle \Phi (x)} notating its cumulative distribution function and ϕ ( x ) {\displaystyle \phi (x)} its probability density function
the Christoffel symbols that describe components of a metric connection; the stack alphabet in the formal definition of a pushdown automaton, or the tape-alphabet in the formal definition of a Turing machine; the Feferman–Schütte ordinal Γ 0; represents: the specific weight of substances; the lower incomplete gamma function
By 1910, inventor Mark Barr began using the Greek letter phi ( ) as a symbol for the golden ratio. [32] [e] It has also been represented by tau ( ), the first letter of the ancient Greek τομή ('cut' or 'section'). [35] Dan Shechtman demonstrates quasicrystals at the NIST in 1985 using a Zometoy model.
In statistics, a standard normal table, also called the unit normal table or Z table, [1] is a mathematical table for the values of Φ, the cumulative distribution function of the normal distribution.
The diameter symbol in engineering, ⌀, is often erroneously referred to as "phi", and the diameter symbol is sometimes erroneously typeset as Φ. This symbol is used to indicate the diameter of a circular section; for example, "⌀14" means the diameter of the circle is 14 units. A clock signal in electronics is often called Phi or uses the ...
Thus, it is often called Euler's phi function or simply the phi function. In 1879, J. J. Sylvester coined the term totient for this function, [14] [15] so it is also referred to as Euler's totient function, the Euler totient, or Euler's totient. Jordan's totient is a generalization of Euler's. The cototient of n is defined as n − φ(n).
In chemistry, phi bonds (φ bonds) are usually covalent chemical bonds, where six lobes of one involved atomic orbital overlap six lobes of the other involved atomic orbital. This overlap leads to the formation of a bonding molecular orbital with three nodal planes which contain the internuclear axis and go through both atoms.