\begin{picture}(width,height)(x offset,y offset)
  .
   picture commands
  .
  \end{picture}

  The picture environment allows you to create just about any kind of
  picture you want containing text, lines, arrows and circles.  You
  tell LaTeX where to put things in the picture by specifying their
  coordinates.  A coordinate is a number that may have a decimal point
  and a minus sign - a number like 5, 2.3 or -3.1416.  A coordinate
  specifies a length in multiples of the unit length \unitlength, so if
  \unitlength has been set to 1cm, then the coordinate 2.54 specifies a
  length of 2.54 centimeters.  You can change the value of \unitlength
  anywhere you want, using the \setlength command, but strange things
  will happen if you try changing it inside the picture environment.

  A positionis a pair of coordinates, such as (2.4,-5), which specifies
  the point with x-coordinate 2.4 and y-coordinate -5.  Coordinates are
  specified in the usual way with respect to an origin, which is
  normally at the lower-left corner of the picture.  Note that when a
  position appears as an argument, it is not enclosed in braces; the
  parentheses serve to delimit the argument.

  The picture environment has one mandatory argument, which is a
  position.  It specifies the size of the picture.  The environment
  produces a rectangular box with width and height determined by this
  argument's x- and y-coordinates.

  The picture environment also has an optional position argument,
  following the size argument, that can change the origin.  (Unlike
  ordinary optional arguments, this argument is not contained in square
  brackets.) The optional argument gives the coordinates of the point
  at the lower-left corner of the picture (thereby determining the
  origin).  For example, if \unitlength has been set to 1mm, the
  command

  \begin{picture}(100,200)(10,20)

  produces a picture of width 100 millimeters and height 200
  millimeters, whose lower-left corner is the point (10,20) and whose
  upper-right corner is therefore the point (110,220).  When you first
  draw a picture, you will omit the optional argument, leaving the
  origin at the lower-left corner.  If you then want to modify your
  picture by shifting everything, you just add the appropriate optional
  argument.

  The environment's mandatory argument determines the nominal size of
  the picture.  This need bear no relation to how large the picture
  really is; LaTeX will happily allow you to put things outside the
  picture, or even off the page.  The picture's nominal size is used by
  TeX in determining how much room to leave for it.

  Everything that appears in a picture is drawn by the \put command.
  The command

  \put (11.3,-.3){ ... }

  puts the object specified by "..." in the picture, with its reference
  point at coordinates (11.3,-.3).  The reference points for various
  objects will be described below.

  The \put command creates an LR box.  You can put anything in the text
  argument of the \put command that you'd put into the argument of an
  \mbox and related commands.  When you do this, the reference point
  will be the lower left corner of the box.