In an expression like f[x], the 'function name' f is itself an expression, and you can treat it as you would any other expression. You can replace names of functions using ...

LogNormalDistribution[\[Mu], \[Sigma]] represents a lognormal distribution derived from a normal distribution with mean \[Mu] and standard deviation \[Sigma].

MatrixExp[m] gives the matrix exponential of m. MatrixExp[m, v] gives the matrix exponential of m applied to the vector v.

InterpolatingFunction[domain, table] represents an approximate function whose values are found by interpolation.

In many kinds of calculations, you may find yourself typing the same input to Mathematica over and over again. You can save yourself a lot of typing by defining a function ...

A variety of moments or combinations of moments are used to summarize a distribution or data. Mean is used to indicate a center location, variance and standard deviation are ...

LogLikelihood[dist, {x_1, x_2, ...}] gives the log-likelihood function for observations x_1, x_2, ... from the distribution dist.

Differentiating a known function gives an explicit result. Differentiating an unknown function f gives a result in terms of f'. Mathematica applies the chain rule for ...

MathLink is a protocol for exchanging symbolic expressions. The Mathematica-level MathLink functions can be used with any MathLink-enabled external program, including ...

Pattern matching makes possible some of the most succinct and elegant programs in the Mathematica language—immediately compressing large numbers of conditional cases into ...