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01. Notation

Vector

A vector is an ordered tuple of cells which represents a orientated distance.

We write vectors as column vectors by default, that is:

{\bf v}:=\begin{pmatrix} x \\ y \\ z \end{pmatrix}

A vector uniquely represents the line from the origin of the coordinate system to a point.

Algebra

  • Addition.
  • Cross Product and Scalar Product.

Field

A field is a physical value which changes from place to place.

Scalar Field

A scalar field does not discriminate the place or direction, it acts the same on any point in space.

Vector Field

For each point in space, a different vector value is possible.

Differentiation

... of a scalar field F on the variable x

÷{d}{dx}F=\lim_{h\rightarrow 0} ÷{F(x+h)-F(x)}{h}

... of a scalar field F on all its variables

(∇⃗F)_i:=÷{d}{dx_i}F=\lim_{h\rightarrow 0} ÷{F(x_i+h)-F(x_i)}{h}

Kronecker Delta

δ_{i,j}:={1,i=j; 0,i≠j}

Integration

TODO path integral

TODO area integral

Gauß' law

∫_V ∇⃗∙D⃗⋅dV=∮_{δV} D⃗∙n⃗⋅dS

Green's law

∫_{D} ((÷{∂}{∂x}g)-(÷{∂}{∂y}f))⋅dV=∮_{∂D} (f⋅dx+g⋅dy)

Stokes' law

∫_Q (∇⃗⨯F⃗)∙n⃗_2⋅dS=∮_{∂Q} F⃗∙n⃗⋅ds

(where n is the unit normal).

Author: Danny (remove the ".nospam" to send)

Last modification on: Thu, 09 May 2013 .