TrimmedMean[list, f] gives the mean of the elements in list after dropping a fraction f of the smallest and largest elements.TrimmedMean[list, {f_1, f_2}] gives the mean when ...
Tr
(Built-in Mathematica Symbol) Tr[list] finds the trace of the matrix or tensor list. Tr[list, f] finds a generalized trace, combining terms with f instead of Plus. Tr[list, f, n] goes down to level n in ...
UndirectedEdge[u, v] or u \[UndirectedEdge] v represents an undirected edge of a graph with vertices u and v.
UndirectedGraphQ[g] yields True if the graph g is an undirected graph and False otherwise.
UniformGraphDistribution[n, m] represents a uniform graph distribution on n-vertex, m-edge graphs.
UnitBox
(Built-in Mathematica Symbol) UnitBox[x] represents the unit box function, equal to 1 for |x| <= 1/2 and 0 otherwise.UnitBox[x_1, x_2, ...] represents the multidimensional unit box function, equal to 1 if ...
UnitTriangle[x] represents the unit triangle function on the interval |x| <= 1 .UnitTriangle[x_1, x_2, ...] represents the multidimensional unit triangle function on the ...
UnitVector[k] gives the two-dimensional unit vector in the k\[Null]^th direction.UnitVector[n, k] gives the n-dimensional unit vector in the k\[Null]^th direction.
UpperTriangularize[m] gives a matrix in which all but the upper triangular elements of m are replaced with zeros. UpperTriangularize[m, k] replaces with zeros only the ...
lhs ^:= rhs assigns rhs to be the delayed value of lhs, and associates the assignment with symbols that occur at level one in lhs.