First (Built-in Mathematica Symbol)

First[expr] gives the first element in expr.

Operations on Vectors (Mathematica Guide)

Mathematica represents vectors as lists, and never needs to distinguish between row and column cases. Vectors in Mathematica can always mix numbers and arbitrary symbolic or ...

$MessageList (Built-in Mathematica Symbol)

$MessageList is a global variable that gives a list of the names of messages generated during the evaluation of the current input line.

Expression Structure (Mathematica Guide)

A foundational idea in Mathematica is that all expressions—whatever they may represent—ultimately have a uniform tree-like structure.

Conditionals (Mathematica Guide)

Mathematica's symbolic character allows a powerful unification of the notion of conditionals in programming and in mathematics.

DefaultElement (Built-in Mathematica Symbol)

DefaultElement is an option for Grid and related constructs which specifies what to insert when a new element is interactively created.

Introduction to Patterns (Mathematica Tutorial)

Patterns are used throughout Mathematica to represent classes of expressions. A simple example of a pattern is the expression f[x_]. This pattern represents the class of ...

ListContourPlot (Built-in Mathematica Symbol)

ListContourPlot[array] generates a contour plot from an array of height values. ListContourPlot[{{x_1, y_1, f_1}, {x_2, y_2, f_2}, ...}] generates a contour plot from values ...

ElementData (Built-in Mathematica Symbol)

ElementData["name", " property"] gives the value of the specified property for the chemical element " name".ElementData[n, " property"] gives the specified property for the ...

Diagonal (Built-in Mathematica Symbol)

Diagonal[m] gives the list of elements on the leading diagonal of the matrix m.Diagonal[m, k] gives the elements on the k\[Null]^th diagonal of m.