FPLOT.DOC

C-Hook Name: fplot.dll/txt

Date: July 18, 1997

Programmer: CNC Software, Inc.

Simple demonstration:

From the fplot main menu, select "Get eqn", then enter "sine.eqn" as the 
file name.  Select "Plot it" to create line segments that comprise one cycle
of a sine wave.  Press Alt-F1 to fit the line segments to the screen.

Description:

Fplot is a function plotting program.  It draws equations and optionally
creates corresponding geometry (points, lines, splines, NURBS curves,
parametric surfaces or NURBS surfaces).  The equations are entered with
ordinary algebraic notation.  The following functions and constants are 
available:

  (x)       Parentheses     (highest precedence)

  function                  (lower precedence)

  -x        Unary minus     (lower precedence)
  x ^ y     Exponentiation  

  x * y     Multiplication  (lower precedence)
  x / y     Division

  x + y     Addition        (lowest precedence)
  x - y     Subtraction

  abs (x)   Absolute value
  sqrt (x)  Square root
  sin (x)   Sine
  cos (x)   Cosine
  tan (x)   Tangent
  asin (x)  Arc sine
  acos (x)  Arc cosine
  atan (x)  Arc tangent
  exp (x)   e^x
  ln (x)    Natural log
  log (x)   Log base 10
  
Predefined variables

  pi        3.141592653589793
  e         2.718281828459045

Main menu:

  Edit eqn        
  Get eqn
  Save eqn
  Vars             
  Angle  D/R      
  Origin
  Geometry         
  Plot it          
  Trace Y/N

Edit eqn:

  Allows the user to enter or edit a multi-line equation.

Get eqn:

  Reads equations from a file (default extension is .eqn)

Save eqn:

  Writes equations to a file.

Vars:

  Defines one or two variables (one if Geometry is set to Draw Only,
  Points, Lines, Splines or NURBS curve; two if Geometry is set to
  any Surface option).

    FPLOT:  Variable definition
    Var name
    L. limit
    U. limit
    Step size

       or

    FPLOT:  Variable definition
    Var name 1
    L. limit 1
    U. limit 1
    Step size1

    Var name 2
    L. limit 2
    U. limit 2
    Step size2

Angle:

  Toggles between degrees and radians.

Origin:

  Defines a point that is added to the curve or surface.

Geometry:

  FPLOT:  Geometry type
  Draw
  Points
  Lines
  Spline
  Nurbs curve
  Draw surf
  Pts surf
  Param surf
  Nurbs surf

Plot it:

  Evaluate equations and draw or create appropriate geometry.

Trace:

  If trace is enabled, the equation, display parameters and variable
  values are written to fplot.log and displayed after Plot it is selected.

Sample equations:

  y = x^2      Parabola

  x = y^2

  z = x^3      Cubic

  x = cos(t)   Helix
  y = sin(t)
  z = t

  x = 2.0 * cos(t)   Ellipse
  y = sin(t)


Reading formulas from a file: Ex:

  angles = degrees / radians

  geometry = draw
             points
             lines
             spline
             nurbs
             draw_surf
             points_surf
             parametric_surf
             nurbs_surf

  step_var1 = t1
  step_size1 = 0.1
  lower_limit1 = 0.0
  upper_limit1 = 5.0

  step_var2 = t2
  step_size2 = 0.1
  lower_limit2 = 0.0
  upper_limit2 = 5.0

  origin = 0, 0, 0

The following samples files are included with fplot:

    candy.eqn       A surface that resembles a piece of wrapped candy.
    cossurf.eqn     A surface: z = cos(x^2 + y^2)
    drain.eqn       A surface that resembles a drain.
    chip.eqn        A surface that resembles a potato chip.
    ellipsd.eqn     An ellipsoid.
    invol.eqn       An involute curve.
    sine.eqn        A sine curve: y = sin(x)
    tube.eqn        A tubular surface.

Distributor:  CNC Software
              344 Merrow Road
              Tolland, CT 06084-9970

Contact:      CNC Software
Phone:        (860) 875-5006