Content and pages maintained by: Jim Lesurf (jcgl@st-and.demon.co.uk)using HTMLEdit and TW on a StrongARM powered RISCOS machine.
/* input from file */
import java.applet.*;
import java.awt.*;
import java.io.*;
import java.lang.*;
public class jlsq extends Applet{
String relName;
File fl = new File(" ");
Font theFont = new Font("TimesRoman",Font.BOLD,20);
Font smallFont = new Font("TimesRoman",Font.PLAIN,18);
Font italicFont = new Font("TimesRoman",Font.ITALIC,18);
FileInputStream from = null;
byte[] buffer = new byte[4096];
int bytes_read, count, i, ils, ixydiv, num_pairs, ip;
int ytext;
StringBuffer xsbuf = new StringBuffer(0);
StringBuffer ysbuf = new StringBuffer(0);
char ch;
double x[] = new double[100];
double y[] = new double[100];
double xmax,ymax,xmin,ymin;
double a,b,sumx,sumy,sumxy,sumx2;
int redx0,redy0,redw,redh;
public void init() {
relName=getCodeBase().toString()+getParameter("datafile").toString();
relName=fixup(relName);
fl = new File(relName);
get_file_input();
analyse();
}
public void get_file_input() {
if (fl.exists()) {
System.out.print("file found");
}
else
{
System.out.print("the input file = "+relName+" not found");
}
count=0;
try {
from = new FileInputStream(fl);
while ((bytes_read = from.read(buffer)) != -1)
{
count=bytes_read;
}
}
catch (FileNotFoundException e) { ; }
catch (IOException e) { ; }
finally {
if (from != null ) try { from.close(); } catch (IOException e) { ; }
}
i=0; ip=0; ils=0; ytext=120;
while ((char)buffer[i] != '*')
{
xsbuf.setLength(0);
ysbuf.setLength(0);
while ( (ch=(char)buffer[i]) != ',')
{
if (ch != ' ') xsbuf.append(ch);
i=i+1;
}
i=i+1;
ixydiv=i;
while ( (ch=(char)buffer[i]) != '\n')
{
if (ch != ' ') ysbuf.append(ch);
i=i+1;
}
ysbuf.append('\0');
i=i+1;
ip=ip+1; ils=i;
try {
x[ip]=Double.valueOf(xsbuf.toString()).doubleValue();
}
catch (ParseException e) {
x[ip]=-99.0;
}
try {
y[ip]=Double.valueOf(ysbuf.toString()).doubleValue();
}
catch (ParseException e) {
y[ip]=-99.0;
}
}
num_pairs=ip;
}
public String fixup(String sin) {
String sout;
int slen,si;
char chs;
slen=sin.length();
sout="";
si=6;
while (si<slen)
{
chs=sin.charAt(si);
if (chs == '/' ) { chs='.'; }
sout=sout+chs;
si=si+1;
}
return sout;
}
public void analyse() {
int iap;
double fnp;
iap=1;
xmax=-9999.0; xmin=9999.0;
ymax=-9999.0; ymin=9999.0;
sumx=0.0; sumy=0.0; sumxy=0.0; sumx2=0.0;
while (iap <= num_pairs) {
if ( x[iap] > xmax ) xmax=x[iap];
if ( x[iap] < xmin ) xmin=x[iap];
if ( y[iap] > ymax ) ymax=y[iap];
if ( y[iap] < ymin ) ymin=y[iap];
sumx=sumx+x[iap];
sumy=sumy+y[iap];
sumxy=sumxy+x[iap]*y[iap];
sumx2=sumx2+x[iap]*x[iap];
iap=iap+1;
}
fnp=(double)num_pairs;
b=fnp*sumxy-sumx*sumy;
a=fnp*sumx2-sumx*sumx;
b=b/a;
a=sumy-b*sumx;
a=a/fnp;
}
public void paint(Graphics g) {
g.setColor(new Color(0,0,0));
g.setFont(theFont);
if (fl.exists()) {
g.drawString("bytes read = "+bytes_read,10,80);
g.drawString("input file = "+relName,10,100);
draw_graph(g);
}
else
{
g.drawString("file not found!", 50, 50);
g.drawString("see javaout",50,70);
}
}
public void draw_graph(Graphics gin) {
int x0, y0, wide, high, igp, edge;
int xp, yp, ye, xe;
double xscale,yscale;
StringBuffer osbuf = new StringBuffer(0);
x0=20; y0=20; edge=10;
wide=400; high=300;
gin.setColor(new Color(255,255,255));
gin.fillRoundRect(1,1,539,399,20,20);
gin.setColor(new Color(0,0,0));
gin.drawRoundRect(1,1,539,399,20,20);
gin.setColor(new Color(180,180,255));
gin.fillRect(x0-edge,y0-edge,wide+2*edge,high+2*edge);
gin.setColor(new Color(0,0,255));
gin.drawRect(x0-edge,y0-edge,wide+2*edge,high+2*edge);
xscale=(double)wide;
xscale=xscale/(xmax-xmin);
yscale=(double)high;
yscale=yscale/(ymax-ymin);
igp=1;
while (igp <= num_pairs)
{
xp=(int)((x[igp]-xmin)*xscale);
yp=(int)((y[igp]-ymin)*yscale);
gin.drawOval(x0+xp-2,y0+high-yp-2,6,6);
igp=igp+1;
}
xp=(int)((x[1]-xmin)*xscale);
yp=(int)(((a+b*x[1])-ymin)*yscale);
xe=(int)((x[num_pairs]-xmin)*xscale);
ye=(int)(((a+b*x[num_pairs])-ymin)*yscale);
gin.setColor(new Color(0,180,0));
gin.drawLine(x0+xp,y0+high-yp,x0+xe,y0+high-ye);
gin.drawLine(x0+xp+1,y0+high-yp,x0+xe+1,y0+high-ye);
redx0=x0+wide+2*edge; redy0=y0+high-redh; redw=90; redh=25;
gin.setColor(new Color(220,255,80));
gin.fillRoundRect(redx0,redy0,redw,redh,10,10);
gin.setColor(new Color(0,0,0));
gin.drawRoundRect(redx0,redy0,redw,redh,10,10);
gin.drawString("Replot!",redx0+20,redy0+redh-8);
gin.setColor(new Color(220,180,220));
gin.fillRoundRect(redx0,y0-edge,redw,high-redh-16,10,10);
gin.fillRoundRect(x0-edge,y0+high+24,wide+3*edge+redw,25,10,10);
gin.setColor(new Color(0,0,0));
gin.drawRoundRect(redx0,y0-edge,redw,high-redh-16,10,10);
gin.drawRoundRect(x0-edge,y0+high+24,wide+3*edge+redw,25,10,10);
gin.setFont(smallFont);
gin.drawString("Fit to:",redx0+8,y0+8);
gin.setFont(italicFont);
gin.drawString("y = ax + b",redx0+8,y0+24);
gin.drawString("a =",redx0+8,y0+50);
gin.drawString("b =",redx0+8,y0+100);
osbuf.append(String.valueOf(b));
osbuf.setLength( osbuf.toString().indexOf('.') + 5 );
gin.setFont(smallFont);
gin.drawString(" "+osbuf,redx0+8,y0+70);
osbuf.setLength(0);
osbuf.append(String.valueOf(a));
osbuf.setLength( osbuf.toString().indexOf('.') + 3 );
gin.setFont(smallFont);
gin.drawString(" "+osbuf,redx0+8,y0+120);
gin.drawString("Input file = "+relName,x0,y0+high+42);
gin.setFont(theFont);
gin.drawString(num_pairs+ " points",redx0+8,y0+200);
}
public boolean mouseDown(Event mev, int mx, int my) {
if ( (mx>=redx0) && (mx<=(redx0+redw)) && (my>=redy0) && (my<=(redy0+redh)))
{
get_file_input();
analyse();
repaint();
}
return true;
}
}
Content and pages maintained by: Jim Lesurf (jcgl@st-and.demon.co.uk)