Jcalcomp: Calcomp Simulator in Java

Ver. 0.99         January. 5,1998
Hiroshi Sakuta
1-276 MIT
Dept. of Civil & Environmental Engineering
Phone) 617-258-0808
hsakuta@mit.edu

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Samples

Fig001 (Coordinate system)
Fig002 (Use number(), symbol())
Fig003 (Linear graph)
Fig004 (Log-Log,Semi-Log graph)
Fig005 (Contour plotting)
Fig006 (3D Plotting)
Fig007 (3D Projection Plane)
Fig008 (3D Symbol and Number)
Fig009 (3D Ray Tracing)
 
Jcalcomp class
Projection Class
Contour Class
Tensor Class
Vector Class
Vector2D class

Preface

"Jcalcomp" simulator is developed mainly for Calcomp plotter users. It is composed with class libraries which have common methods with subroutines and/or functions in the flat bed pen plotter, which has been used as a graphical output device from the main-frame age. Many potential programmers used to make their own codes for Calcomp plotter.
Facilities for Calcomp plotter are extended to Java graphical environment here. Then, all functions are implemented methods in class libraries. The features of this class library are 1) interactivity (controlled by scroll bar or radio button on a browser), 2) perspective/isometric projective view and its animation, 3) ray tracing 4) contour plotting, and 5) original vector fonts for ASCII character sets which can be applied by users to their superset.  The style of code seems to be classic but understandable for beginners.

The language

The language applied for this simulator is Java. The reasons of this application are: 1) a compact load module, 2) friendly interface of Web documents, 3) portability, and 4) good advantage in graphical interface. Java is, of course, an Object Oriented Language, and programming in Java requires some knowledge of this subject. However, this simulator provide a kind of template and will be understandable for C/FORTRAN programmers. This means that a lot of graphic codes for Calcomp plotter in archives can get their role in Web contents. Also, senior programmers can make their graphic code in Java and give advise to younger programmers in this field.
There are many textbook for OOPS(Object Oriented Programming System), of which B. Meyer's work is very instructive.

Class and Method

In this version, the class library is not clearly separated from user code , and is supplied as a source library, which means that users can make their own class library with the source code.
The following descriptions, therefore, are tentative until version 1.0.

Coordinate system

This class library applies three types of coordinates systems, which are well known for graphic programmers and, of course, for Calcomp programmers.

1) Screen coordinates

Screen monitor coordinates correspond to a pixcel-wise bitmap picture. The origin is specified by its launching browser/viewer, and usually the top-left corner in the browser/viewer is default. The increment of coordinate is then an integer number.

2) World coordinates

World coordinates are the user's section paper. Users can fit it to  screen coordinates by specification of two points, which are (x,y) coodinates of top-left and lower-right corner of section paper corresponding to the screen coordinates. Our mathematical coordinate system has opposite direction to the screen's y-coordinate(vertical), which are considered in this library. Users can use their section paper normally.
3D coordinates are used in this library for perspective or isometric projections. Then the world coordinate is used in projection viewing. The 3D users view objects through this section paper.(see Fig001)

3) User's coordinates

The user's coordinate is local coodinates in the section paper written by them.
The local coordinate system is usually applied for curve plotting of some functions and representations of experimental results. Then these coordinates are only for curve plotting. Users can draw their curve by methods of "lline" and "lgline". The former is for linear plotting and the latter is for logarithm scale. Both have own axis presentation methods "axis" and "lgaxis".
In 3D viewing of curve plotting, however, the user's coordinate is not applied.  If 3D coordinates has user's coordinate system, the projection plane( section paper) has to make a new coordinate system corresponding to 3D user's coordinate system. While this conversion is not difficult for the computer, conversion of user's own coordinate to world coordinates is more comprehensive for the user. This means user have to calculate the 3D coordinates without local coordinates in the section paper. In spite of this, there are two 3D axis plotting method, which are "paxis" and "plgaxis".
They are corresponding to "axis" and "lgaxis" in 2D, respectively.

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Class and Method description

Jcalcomp

Syntax
public abstract class Jcalcomp

Description
This Jcalcomp class is a basic engineering drawing tool by usage of Graphics. It generates user's original coordinates, contour line graph and 3D graph.
Jcalcomp is extended from Applet class and user should make their own class extended from Jcalcomp.
This class is named after Calcomp plotter library, which has been used as a flatbed plotter library in FORTRAN library.

MEMBER SUMMARY

Constructors & Destructors

Jcalcomp()        Construct a new Calcomp simulator area

Basic 2D Drawing Methods

marker()        draw plotting symbol, whose identification point is its center

number()        draw double number in arbitrary format

symbol()        draw ASCII character in vector font

u_plot()         Basic plotting method
 

2D Function Drawing Methods

arcarrow()        draw arrow along an arc in arbitrary shape and direction

arrow()        draw arrow in arbitrary shape and direction

axis()            draw linear axis in world coordinates

Dimension()    draw design dimensions with title

f_rect()        draw rectangle filled forward color specified with 2 corner points

lgaxis()        draw logarithm axis in world coordinates

lgscale()        output converting factor from user's linear coordinates to world ones.

lgline()            draw 2D logarithm line in user's coordinate by log/log, log/linear, and linear/log for x/y.
lline()            draw 2D line in user's coordinates by linear scale

scale()           output converting factor from user's linear coordinates to world ones.

u_rect()        draw rectangle specified by 2 corner point

lattice()        draw square lattice

SectionPaper()    draw section paper on white paper
 

2D Contour Line Drawing Methods

mshplt()    draw 2D mesh system for contour plotting in physical and virtual coordinates.

contor()        draw 2D contour line in physical and virtual coordinates.

void Jcalcomp()

SYNTAX :
            Jcalcomp(int x_dim,int y_dim,double wid,int igx0,int igy0,int igx1,int igy1,double gx0,
                            double gy0)
            Jcalcomp(int x_dim,int y_dim,double wid,double gx0,double gy0)
            Jcalcomp(int x_dim,int y_dim)
            Jcalcomp(int x_dim,int y_dim,double wid)
            Jcalcomp()

DESCRIPTION : Fix 2 points specified by top-left and bottom-right corners. Corresponding world coordinate system is developed. (see Fig.1)

PARAMETERS :
x_dim       width of  outer boundary dimension in screen coordinate(see Fig.1)default=300
y_dim       height of  outer boundary dimension in screen coordinate(see Fig.1) default=200
igx0          specified top-left corner x coordinate  (see Fig.1)default=0
igy0          specified top-left corner y coordinate  (see Fig.1)default=0
igx1          specified bottom-right corner x coordinate (see Fig.1)default=x_dim
igy1            specified bottom-right corner y coordinate (see Fig.1)default=y_dim
gx0             origin in world x coodinate (see Fig.1)default=0.
gy0             origin in world y coodinate (see Fig.1)default=0.
wid             width corresponding to igx1-igx0 in world cordinate(see Fig.1)default=30.

RETURNS : none

SEEALSO : Vector2D class

EXAMPLE :

import java.applet.*;
import java.awt.*;

//******************************************
public class Fig001 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig001()
//==========================================
  {
   super(400,350,35.,0.,0.);
  }
//==========================================
  public void init()
//==========================================
  {
 setLayout( null );
  }
//==========================================
  public void paint( Graphics g )
//==========================================
  {
   double x0=3.,x1=20.,y0=3.,y1=25.,sun=3.;
   int i;
// double dx=15.0/(double)(maxp-1);
 Dimension(g,10.,20.,12.,17.,3.,4,"ABC");
    g.setColor( Color.yellow );
 f_rect(g,x0,y0,x1,y1);

    g.setColor( Color.cyan );
 f_rect(g,x0+sun,y0+sun,x1-sun,y1-sun);

    g.setColor( Color.black );
 Font f1=new Font("TimesRoman",Font.BOLD,12);

    g.setColor( Color.black );

 Dimension(g,new Vector2D(x1,y0),new Vector2D(x1,y1),-sun,4,"ABC");
 Dimension(g,x0,y1,x1,y1,sun,4,"ABC");
 Dimension(g,x0+sun,y0+1.5*sun,x1-sun,y0+1.5*sun,0.,4,"ABC");

 u_plot(g,x0+sun,y1-sun,3);
 u_plot(g,x0+1.5*sun,y1-.7*sun,2);
 u_plot(g,x0+3.5*sun,y1-.7*sun,2);

 u_plot(g,x1-sun,y0+sun,3);
 u_plot(g,x1-1.5*sun,y0+.6*sun,2);
 u_plot(g,x0+2.5*sun,y0+.6*sun,2);

 u_plot(g,x0+sun,y0+sun,3);
 u_plot(g,x0+1.5*sun,y0-.6*sun,2);
 u_plot(g,x0+3.5*sun,y0-.6*sun,2);

 marker(g,x0+sun,y1-sun,5);
 marker(g,x1-sun,y0+sun,5);
 marker(g,x0+sun,y0+sun,5);

    g.setColor( Color.red );
 symbol(g,x1+.4*sun,y0+.35*(y1-y0),1.,"y_dim",90.,5);
 symbol(g,x0+.35*(x1-x0),y1+.5*sun,1.,"x_dim",0.,5);
 symbol(g,x0+2.6*sun,y0+.65*sun,"(jgx1,jgy1)");
 symbol(g,x0+1.5*sun,y1-.6*sun,"(jgx0,jgy0)");

    g.setColor( Color.black );
 symbol(g,x0+.35*(x1-x0),y0+1.6*sun,"Width");
 symbol(g,x0+1.7*sun,y0-.55*sun,"(gx01,gy01)");

 Font f=new Font("TimesRoman",Font.BOLD,24);
 g.setFont(f);

    g.setColor( Color.yellow );

  }
}

void u_plot()

PURPOSE : 2D Plotting in World Coordinates

SYNTAX :
            plot(Graphics g,double x,double y,int n)
            plot(Graphics g,Vector2D V,int n)

DESCRIPTION :
            Pen is moving in the state of up or down

PARAMETERS :

g            Graphic port
V            2D vector coordinate
x            x world coordinate
y            y world coordinate
n            pen mode =2:    pen down;    =3: pen up;    =-3: move origin

SEEALSO : Vector2D class

EXAMPLE :see example of Jcalcomp() 

void SectionPaper()

SYNTAX :
        public void SectionPaper(Graphics g,   double x0,double y0, double x1,double y1,
                        double dx, double dy, int pitch0, int pitch1)
DESCRIPTION :

PARAMETERS :
        g                Graphic port
        x0            a corner's x coordinate of the section paper
       y0            a corner's y coordinate of the section paper
        x1            opposite corner's x coordinate of the section paper
        y1            opposite corner's y coordinate of the section paper
       dx            minimum pitch of x-direction
       dy            minimum pitch of y-direction
        pitch0    fine pitch(>0)    drawn in lightgray color
        pitch1    rough pitch(>0)    drawn in darkgray color
 
RETURNS : none

SEEALSO : lattice,Graphics class,Color class

EXAMPLE : see example of Jcalcomp()

void lattice()

SYNTAX :
        public void lattice(Graphics g,   double x0,double y0, double x1,double y1, double dx, double dy)
DESCRIPTION :

PARAMETERS :
        g                Graphic port
        x0            a corner's x-coordinate of the lattice
       y0            a corner's y-coordinate of the latice
       x1            opposite corner's x-coordinate of the lattice
        y1            opposite corner's y-coordinate of the lattice
       dx            pitch of x-direction
       dy            pitch of y-direction
 
RETURNS : none

SEEALSO : SectionPaper(),Graphics class,Color class

EXAMPLE : see example of Jcalcomp() 

void arcarrow()

SYNTAX :
          public void arcarrow(Graphics g,   Vector2D e0, Vector2D e1,double angle,   int mode)
DESCRIPTION :

PARAMETERS :
        g                Graphic port
        mode        arrow drawing mode =1: no arrow;    =2: one arrow at the end; =3:one arrow at the start;  =4: arrows at both end ; defalt =1
        e0        =new Vectoe2D(x0,y0)  center of arc
        e1        =new Vectoe2D(x1,y1)  start radial vector from center
    angle       angle of arrow in degree
RETURNS : none

SEEALSO : Vector2D class ,Dimension()  ,Graphics class,Color class

EXAMPLE : 
 

import java.applet.*;
import java.awt.*;
import java.util.Date;

//******************************************
public class Fig050 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig050()
//==========================================
  {
   super(600,500,40.,-5.,-5.);
  }
//==========================================
 public void init()
//==========================================
 {
 }
//==========================================
public void paint(Graphics g)
//==========================================
{
 g.drawString("Fig050: arcarrow",10,450);
 for(int i=0;i<360;i+=30)
 {
  double angs=(double)i*Math.PI/180.;
  for(int j=30;j<360;j+=30)
  {
   double ange=(double)j*Math.PI/180.;
   arc_arrow(g,
    new Vector2D((double)i/10.,(double)j/10.0),
    new Vector2D(Math.cos(angs),Math.sin(angs)),
    (double)j,(i/30)%4+1);
  }
 }
}
//==========================================
}

void arrow()

SYNTAX :
        public void arrow(Graphics g,   double x0,double y0, double x1,double y1,   int mode)
        public void arrow(Graphics g,   Vector2D e0, Vector2D e1,   int mode)
DESCRIPTION :

PARAMETERS :
        g                Graphic port
        x0            arrow starting x world coordinate
        y0            arrow starting y world coordinate
        x1            arrow ending x world coordinate
        y1            arrow starting y world coordinate
        mode        arrow drawing mode =1: no arrow;    =2: one arrow at the end; =3:one arrow at the stat;  =4: arrows at both end ; defalt =1
        e0        =new Vectoe2D(x0,y0)
        e1        =new Vectoe2D(x1,y1)
RETURNS : none

SEEALSO : Vector2D class ,Dimension()  ,Graphics class,Color class

EXAMPLE : see example of Jcalcomp() 

void u_rect()

SYNTAX :
        public void u_rect(Graphics g,   double x0,double y0, double x1,double y1)
DESCRIPTION :
        Specified by 2 vertex( left-bottom and right-top in world coordinates)
PARAMETERS :
        g                Graphic port
        x0             left-bottom x world coordinate
        y0             left-bottom y world coordinate
        x1             right-top x world coordinate
        y1             right-top y world coordinate
RETURNS : none

SEEALSO : Vector2D class ,f_rect()

EXAMPLE : see example of Jcalcomp() 

void f_rect()

SYNTAX :
        public void f_rect(Graphics g,   double x0,double y0, double x1,double y1)
DESCRIPTION :
        Specified by 2 vertex( left-bottom and right-top in world coordinates)
PARAMETERS :
        g                Graphic port
        x0             left-bottom x world coordinate
        y0             left-bottom y world coordinate
        x1             right-top x world coordinate
        y1             right-top y world coordinate
RETURNS : none

SEEALSO : Vector2D class ,u_rect() ,Graphics class,Color class

EXAMPLE : see example of Jcalcomp() 

void Dimension()

SYNTAX :
   public void Dimension(Graphics g,   double x0,double y0, double x1,double y1,double supl,
   int mode,String title)
   public void Dimension(Graphics g,   Vector2D e0, Vector2D e1,double supl,   int mode,String title)

DESCRIPTION : line parallel to specified 2 points are e0(x0,y1) and e1(x1,y1) and supplement lines start from e0 and e1 of length supl and draw title on them

PARAMETERS :
        g                Graphic port
        x0            arrow starting x world coordinate
        y0            arrow starting y world coordinate
        x1            arrow ending x world coordinate
        y1            arrow starting y world coordinate
        mode        arrow drawing mode =1: no arrow;    =2: one arrow at the end; =3:one arrow at the stat;  =4: arrows at both end ; defalt =1
        e0        =new Vectoe2D(x0,y0)
        e1        =new Vectoe2D(x1,y1)
        supl        length of supplemental lines which are 90 degree rotated from the vector e0 to e1.
                        If supl<0, it means -90 degree rotation
        title        title on the arow
RETURNS : none

SEEALSO : Vector2D class ,Dimension()

EXAMPLE : see example of Jcalcomp() 

void symbol()

DESCRIPTION :
 

PARAMETERS :

x            Starting point of string. The x coordinate of Left bottom corner of the first charcter.
y            Starting point of string. The y coordinate of Left bottom corner of the first charcter.
h            The height of characters.
text        String to be painted. If  the 1st syntax is applied, Vector font is chosen.
              If 2nd, the current system font is chosen which is horizontal only.
theta       The angle of string in degrees from horizontal left to right direction.
in            The number of charactors in the string.
 

SEEALSO : Vector2D class, number()

EXAMPLE : see example of Jcalcomp() 

void number()

SYNTAX :
void number(Graphics g,double x,double y,double h, double fpn,double theta,int n)
 

DESCRIPTION :

PARAMETERS :

x           Starting point of number. The x coordinate of Left bottom corner of the first charcter.
y            Starting point of number. The y coordinate of Left bottom corner of the first charcter.
h            The height of characters.
fpn        The objective double number.
theta        The angle of number string in degree from horizontal left to right direction.
n            The column under decima point. It n<0, the number is rounded by n power of 10.

SEEALSO : symbol()

EXAMPLE : 

import java.applet.*;
import java.awt.*;

//******************************************
public class Fig002 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig002()
//==========================================
  {
   super(400,150,35.,0.,0.);
  }
//==========================================
  public void init()
//==========================================
  {
 setLayout( null );
  }
//==========================================
  public void paint( Graphics g )
//==========================================
  {
   double fpn=1234.56789;

   for(int n=4;n>-3;n--)
   {
    symbol(g,2.,(double)n*1.,.8,"n=",0.,2);
    number(g,4.,(double)n*1.,.8, (double)n,0.,-1);
    number(g,8.,(double)n*1.,.8, fpn,0.,n);
   }
  }
}

void marker()

SYNTAX : void marker(Graphics g,double x,double y,int n)
 

DESCRIPTION : The shape of markers are controlled by n.The height is preserved value h2 in class.

PARAMETERS :
x            The x coordinate of center of the marker.
y            The y coordinate of center of the marker.
n            Specify the shape of marker
                0:   none drawn
                1:   Circle
                2:   Square
                3:  none drawn
                4:  Filled Square
                5:  Filled circle
                6:  Filled triangle
 

RETURNS : none

SEEALSO : lline(),lgline()

EXAMPLE :

void axis()

SYNTAX : void axis(Graphics g,  double x0,double y0,double d,double t, double theta,String title,
                int n,int m,int md,double sm,double smd)
 

DESCRIPTION : User has to recognize the difference between "world coordinate" and "User coordinate". This axis method is the interface of them. x0, y0, d, and t are in world coordinate system, and
sm and smd are in User Coordinate system.

PARAMETERS :

g                Graphic port
x0             Starting point x coordinate(in World Coodinate system)
y0             Starting point y coordinate(in World Coodinate system)
d               Abs(t) is length and increment of supplemental line. If t>0, axis is drawn
                    in the direction of clockwise.
                  If t<0, counter-clockwise.
t               Length of axix (in World Coodinate system)
theta          The Direction of axis. (in degree)
title            Title string. It is located at the place specified by t.
n                Number of characters of title
m               Initial position to print value
md             Increment of supplemental line
sm             Starting value printed
smd           Increment of printed value
 

SEEALSO : axis(),scale(),marker()

EXAMPLE : see example of lline() 

void lline() 

---

SYNTAX :
void lline(Graphics g,     double xp,double yp,     double[] x,double[] y,     int nn,int isym)
void lline(Graphics g,     Vector2D v0,     Vector2D[] v,     int nn,int isym)

DESCRIPTION :
The coordinate data set is stored in two arrays x[] and y[], respectively. This line has some mode to differenciate it from  another line. Some symbols are  able to plot on each coordinate point. The line can be erased, when users do not need it. The color of line is foreground color, which is not cared in this method.

PARAMETERS :

xp         x minimum coordinate( in World coordinate)
yp         y minimum coordinate( in World coordinate).
v0        Vector2D representation of (xp,yp)
x            array stored x coordinate(in User coordinate)
            x[nn+1]: minimum value or drawing bottom value((in User coordinate)
            x[nn+2]: scale factor( =a length in user coordinate/corresponding world coordinate)
y            array stored y coordinate(in User coordinate)
            y[nn+1]: minimum value or drawing bottom value((in User coordinate)
            y[nn+2]: scale factor( =a length in user coordinate/corresponding world coordinate)
v           Vector2D representation of (x[i],y[i])
nn        Abs(nn) meansthe number of points to be drawn.  (x[0],y[0]) to (x[nn-1],y[nn-1])
            If nn>0, draw line.  If nn<=0, do not.
isym    Specified symbol number(see marker())

SEEALSO : axis(),scale(),marker(),lgaxis()

EXAMPLE :
import java.applet.*;
import java.awt.*;

//******************************************
public class Fig003 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig003()
//==========================================
  {
   super(300,250,35.,-5.,-5.);
  }
//==========================================
  public void init()
//==========================================
  {
 setLayout( null );
  }
//==========================================
  public void paint( Graphics g )
//==========================================
  {
   double fpn=1234.56789;
   int maxp=51;
   double x[]=new double[105],y[]=new double[105];
   double width=30.,height=20.,dx=width/(double)(maxp-1),
   udx=dx/width*4.*Math.PI;
 
   SectionPaper(g,0.,0.,width,height,
    width/(4.*Math.PI)*.5,height/8.,1,2);
 
   u_plot(g,0.,0.,3);u_plot(g,0.,height,2);
   u_plot(g,width,height,2);u_plot(g,width,0.,2);
   u_plot(g,0.,0.,2);
   for(int i=0;i<=maxp;i++)
   {
    x[i]=udx*i;
    y[i]=Math.sin(x[i]);
   }
   x[maxp+1]=0.;   y[maxp+1]=0.;
   x[maxp+2]=(4.*Math.PI)/width;
   y[maxp+2]=4./height;
   for(int i=1;i<=5;i++)
   {
    if(i<4)  lline(g,0.,10.+(i-3)*2.,x,y,maxp,i);
    else  lline(g,0.,10.+(i-3)*2.,x,y,-maxp,i);
    marker(g,0.,-2.-i*1.+.5,i);
    symbol(g,3.,-2-i*1.,"Marker #");
    number(g,10.,-2-i*1.,0.8,(double)i,0.,-1);
   }
   axis(g,0.,0.,1.,width,0.,"x",1,1,5,0.,5.*x[maxp+2]);
   axis(g,0.,0.,-1.,height,90.,"y",1,1,5,-2.,5.*y[maxp+2]);
  }
}

void scale()  

---

DESCRIPTION : The scale factor of linear plotting is calculated by maximum and minimum value of x[]
 between x[0] to x[n] and insert at the last of x array. x[n+1] is mimimum and bottom of graph.
x[n+2] is scale factor of user coodinate/world coordinate. User can calculate these two element by them selves and set by substitution of value.

PARAMETERS :

    x            Array to be scaled
    n            maximum number of element  x to be plotted. It is not coincide to array length.
                    The array length must be n+2 or over
    dx         scale factor of user coodinate/world coordinate

RETURNS : none

SEEALSO : lline(),axis()

EXAMPLE : see example of lline

void lgaxis() 

---

SYNTAX : void lgaxis(Graphics g,   double x0,double y0,double t,double theta,
   int isep,String title,int n,int m)
 

DESCRIPTION : User have to recognize the difference between "world coordinate" and "User coordinate". This lgaxis method is the interface between them. x0, y0, and t are in world coordinate system, and 10**m and 10**(m+isep) are in User logarithm Coordinate system.

PARAMETERS :

x0            Starting point x coordinate(in World Coodinate system)
y0            Starting point y coordinate(in World Coodinate system)
t              length of axis (in World Coodinate system)
theta        The Direction of axis. (in degree)
isep               Abs(isep) is number of power to be developed in t. If isept>0, axis is drawn in the direction of clockwise.
                If isep<0, counter-clockwise.
title            Title string. It is located at the place specified by t and isep.
n              length of title string
m           starting power
 

SEEALSO : lgaxis(),lgscale(),marker()

EXAMPLE : see example of lgline()

void lgline() 

---

PURPOSE :  Draw log-log and semi-log plotting line. This method make it possibleto put  arbitrary scaling and arbitrary size figure  into html documents.

SYNTAX :
void lglline(Graphics g,     double xp,double yp,     double[] x,double[] y,     int nn,int ils,int isym)

DESCRIPTION :
The coordinate data set is stored in two array x[] and y[], respectively. This line has three styles, which are log-log, log-linear, and linear-log in x-y plotting. multiple lines are differenceiated by marker symbols and/or its color. Some marker symbols are be able to plot on each coordinate point. The line can be erased, when users do not need it. The color of line is foreground color, which is not cared in this method.

PARAMETERS :

xp         x minimum coordinate( in World coordinate)
yp         y minimum coordinate( in World coordinate).
x           Array stored x coordinate(in User coordinate)
            x[nn+1]: minimum value or drawing bottom value((in User coordinate)
            x[nn+2]: ils=1 or 2:scale factor( =a length in One power width
                                in world coordinate)
                        ils=3:linear scale factor(=a length in world
                                coordinate/corresponding user coordinate)
                                !CAUTION! inverse of lline()
y            array stored y coordinate(in User coordinate)
            y[nn+1]: minimum value or drawing bottom value((in User coordinate)
            y[nn+2]:  ils=1 or 3:scale factor( =a length in One power width
                                in world coordinate)
                          ils=2:linear scale factor(=a length in world
                               coordinate/corresponding user coordinate)
                                !CAUTION! inverse of lline()
nn        Abs(nn) meansthe number of points to be drawn.
            (x[0],y[0]) to (x[nn-1],y[nn-1])
            If nn>0, draw line.  If nn<=0, do not.
ils         drawing mode
                        x  -  y
            =1   :   log - log
            =2      log  - linear
            =3:     linear - log
isym    Specified symbol number(see marker())
RETURNS : none

SEEALSO : lgaxis(),lgscale(),marker(),axis()

//******************************************
public class Fig004 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig004()
//==========================================
  {
   super(600,300,75.,-5.,-8.);
  }
//==========================================
  public void init()
//==========================================
  {
 setLayout( null );
  }
//==========================================
  public void paint( Graphics g )
//==========================================
  {
   double fpn=1234.56789;
   int maxp=51;
   double x[]=new double[105],y[]=new double[105];
   double width=30.,height=20.,dx=width/(double)(maxp-1),
   udx=dx/width*4.*Math.PI;
   double xmove=5.+width,ymove=-7.-height;
 
   u_plot(g,0.,0.,3);u_plot(g,0.,height,2);
   u_plot(g,width,height,2);u_plot(g,width,0.,2);
   u_plot(g,0.,0.,2);
   for(int i=0;i<=maxp;i++)
   {
    x[i]=udx*i+1.;
    y[i]=2.-Math.sin(x[i]);
   }
// log-log plot
   x[maxp+1]=0.;   y[maxp+1]=0.;
   x[maxp+2]=width/2.;
   y[maxp+2]=height/2.;
   for(int i=1;i<=5;i++)
   {
    if(i<4)  lgline(g,0.,10.+(i-3)*2.,x,y,maxp,1,i);
    else  lgline(g,0.,10.+(i-3)*2.,x,y,-maxp,1,i);
    marker(g,width*.5+3.,8.-i*1.+.5,i);
    symbol(g,width*.5+2.+3.,8.-i*1.,"Marker #");
    number(g,width*.5+2.+10.,8.-i*1.,0.8,(double)i,0.,-1);
   }
   lgaxis(g,0.,0.,width,0.,2,"x(log)",6,0);
   lgaxis(g,0.,0.,height,90.,-2,"y(log)",6,-1);
// log-linear plot
   x[maxp+1]=0.;   y[maxp+1]=0.;
   x[maxp+2]=width/2.;
   y[maxp+2]=1./(10./height);
   for(int i=1;i<=5;i++)
   {
    if(i<4)  lgline(g,xmove,10.+(i-3)*2.,x,y,maxp,2,i);
    else  lgline(g,xmove,10.+(i-3)*2.,x,y,-maxp,2,i);
   }
   lgaxis(g,xmove,0.,width,0.,2,"x(log)",6,0);
   axis(g,xmove,0.,-1.,height,90.,"y",1,1,5,0.,5./y[maxp+2]);
   u_plot(g,width+xmove,0.,3);u_plot(g,width+xmove,height,2);
   u_plot(g,xmove,height,2);
// linear-log plot
   x[maxp+1]=0.;   y[maxp+1]=0.;
   x[maxp+2]=1./((5.*Math.PI)/width);
   y[maxp+2]=height/2.;
   for(int i=1;i<=5;i++)
   {
    if(i<4)  lgline(g,0.,ymove+10.+(i-3)*2.,x,y,maxp,3,i);
    else  lgline(g,0.,ymove+10.+(i-3)*2.,x,y,-maxp,3,i);
   }
   lgaxis(g,0.,ymove,height,90.,-2,"y(log)",6,0);
   axis(g,0.,ymove,1.,width,0.,"x",1,1,5,0.,5./x[maxp+2]);
   u_plot(g,width,ymove,3);u_plot(g,width,ymove+height,2);
   u_plot(g,0.,ymove+height,2);

  }
}

void lgscal() 

---

PURPOSE :

DESCRIPTION : The scale factor of log-log or log-linear plotting is calculated by maximum and minimum value of x[]
 between x[0] to x[n] and insert at the last of x array. x[n+1] is mimimum and bottom of graph.
x[n+2] is scale factor of  world coodinate/user coordinate. User can calculate these two element by them selves and set by substitution of value. The treatment of linear case is different from lline() and scale().
(see lgline())
PARAMETERS :

    x            Array to be scaled
    n            maximum number of element  x to be plotted. It is not coincide to array length.
                    The array length must be n+2 or over
    dx         scale factor of user coodinate/world coordinate

RETURNS : none

SEEALSO : lgline(),lgaxis()

EXAMPLE : see example of lline

void wlattice()

DESCRIPTION :

PARAMETERS :

x,y,dx,dy,m,n

SEEALSO :

EXAMPLE : 

void mshplt() 

---

PURPOSE :

PARAMETERS :

               mode  =0 : Real Mesh
                         <>0 : Virtual Mesh
              frm   <>1 : Draw Boundary Frame only
                        = 1 : Draw Full Mesh
x                        1D Array stored x coordinates of taget area.[i][j] is specified [xdim*i+j]
y                        1D Array stored x coordinates of taget area.[i][j] is specified [ydim*i+j]
f                        1D Array of countour variavle.[i][j] is specified [vdim*i+j]
flg                     1D Array of attribute of each cell ="F" normal(Fuid) ="S" not effective
                        nor draw         (Solid)      .      "B" (Boundary ) is same as "S".

                            [i][j] is specified [fdim*i+j]
m                        Max of array x in target area
n                        Max of array y in target area
xdim                    1st dimension of Array x
ydim                     1st dimension of Array y
fdim                     1st dimension of Array flg
wid                    size of x direction of target area in case of mod=1
hei                    size of y direction of target area in case of mod=1

SEEALSO : contour()

EXAMPLE : see example of contour() 

void fmxmn()

DESCRIPTION :

PARAMETERS :

flg                     1D Array of attribute of each cell ="F" normal(Fuid) ="S" not effective
                        nor draw         (Solid)      .      "B" (Boundary ) is same as "S".
f                        1D Array of countour variavle.[i][j] is specified [vdim*i+j]
m                        Max of array x in target area
n                        Max of array y in target area
lvl                        The number of contour level. see setlvl and stclr
vdim                     1st dimension of Array f
fdim                     1st dimension of Array flg
setlvl                 1D Array of countour level. from 0 to lvl

SEEALSO : contour(),mshplt()

EXAMPLE : see example of contour() 

void contor() 

---

SYNTAX :
void contor(Graphics g,   int mod, double[] x,double[] y,double[] f,   char[] flg,double[] setlvl,   int[] stclr,int[] stlsy,int lvl,int m,int n,  int xdim,int ydim,int vdim,int fdim,  double wid,double hei)
 
void contor(Graphics g,   int mod, double[][] x2dim,double[][] y2dim,double[][] f2dim,   char[][] flg2dim,double[] setlvl,   int[] stclr,int[] stlsy,int lvl,int m,int n,   double wid,double hei)

DESCRIPTION :

Real coordinate system is specified by (x,y) and they are topologically equal to virtual coordinate system.
Then given coordinate system by users is available in both system.
Settings of  the cotour level is user's matter. Maximum of level setting is depends upon array size of setlvl[] and setclr[].While color levels is now fixed to a gradiation series of yellow color, user can choose arbitrary colors in future.

PARAMETERS :

g                         graphic port
mod                    =0 : Real Mesh ,Band
                             1 : Virtual Mesh ,Band
                              -1:  Real Mesh ,Line
                               -2:Virtual Mesh , Line
x                        1D Array stored x coordinates of taget area.[i][j] is specified [xdim*i+j]
y                        1D Array stored x coordinates of taget area.[i][j] is specified [ydim*i+j]
f                        1D Array of countour variavle.[i][j] is specified [vdim*i+j]
flg                     1D Array of attribute of each cell
                            ="F" normal(Fuid)
                            ="S" not effective nor draw (Solid)
                            [i][j] is specified [fdim*i+j]
x2dim                        2D Array stored x coordinates of taget area.[i][j] is specified x2dim[i][j]
y2dim                        2D Array stored x coordinates of taget area.[i][j] is specified y2dim[i][j]
f2dim                        2D Array of countour variavle.[i][j] is specified  f2dim[i][j]
flg2dim                     2D Array of attribute of each cell
                            ="F" normal(Fuid)
                            ="S" not effective nor draw (Solid)
                            [i][j] is specified  flg2dim[i][j]
setlvl                 1D Array of countour level. from 0 to lvl
stclr                    1D Array of color spec. 0 to lvl corresponding setlvl.
                            In case of "Band" mode, i-th color will paint between setlvl[i] and setlvl[i+1]
stlsy                    1D Array.Not effective
lvl                        The number of contour level. see setlvl and stclr
m                        Max of array x in target area
n                        Max of array y in target area
xdim                    1st dimension of Array x
ydim                     1st dimension of Array y
vdim                     1st dimension of Array f
fdim                     1st dimension of Array flg
wid                    size of x direction of target area in case of mod=1
hei                    size of y direction of target area in case of mod=1

SEEALSO : fmxmn(),mshplt(),find()

EXAMPLE : 
import java.applet.*;
import java.awt.*;

//******************************************
public class Fig005 extends Jcalcomp
//******************************************
{
//==========================================
  public  Fig005()
//==========================================
  {
   super(600,300,75.,-30.,-8.);
  }
//==========================================
  public void init()
//==========================================
  {
 setLayout( null );
  }
//==========================================
  public void paint( Graphics g )
//==========================================
  {
 double n;
 int i,j;
 char flg[]=new char[140];
 double wid=4.0;
 double xcur,ycur;
 double x[]= new double[140],
   y[]= new double[140],
   f[]= new double[140],
   setlvl[]=new double[21];
 int  stclr[]=new int[21],
   stlsy[]=new int[21];
 double r0=7.,r1=30.;
 double h1;
 int x_max=10,y_max=10,f_max=10;
 int x_max1=x_max+1,y_max1=y_max+1,f_max1=f_max+1;

    g.setColor( Color.yellow );
 double dx=Math.PI/x_max;
 double dy=(r1-r0)/y_max;
 for(i=0;i<=x_max;i++)
 {
  double costheta=Math.cos(dx*i);
  double sintheta=Math.sin(dx*i);

  for(j=0;j<=y_max;j++)
  {
   double r=r0+dy*j;
   x[i*x_max1+j]=r*costheta;
   y[i*x_max1+j]=r*sintheta;
   f[i*x_max1+j]=(y[i*y_max1+j])*(1.-(r0*r0)/(r*r));
   flg[i*x_max1+j]='F';
  }
 }
 for(i=0;i<=20;i++)
 {
  if(i<10)setlvl[i]=(double)i;
  else setlvl[i]=(double)i*2-10;
  stclr[i]=i*10;
 }
 mshplt(g,
   0,0,
   x,y,flg,
   x_max,y_max,x_max1,y_max1,f_max1,20.,15.);

  contor(g,
   -1,
   x, y, f,
   flg,setlvl,
   stclr,stlsy,20,
   x_max,y_max,
   x_max1,y_max1,f_max1,f_max1,
   20.,15.);
  }
}

int find() 

---

PURPOSE :

DESCRIPTION :

PARAMETERS :

RETURNS :

SEEALSO :

EXAMPLE :