Pascal's Triangle
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<script language="JavaScript1.1">
<!--- Begin script hiding
//	Pascal's Triangle generator with variable rows and factor value
//	written by Stephen Battey - May 1997
//	http://www.oocities.org/Heartland/Plains/5287

//	Modified in June 1997 by Stephen Battey
//	Triangle creation process is now done in the background



function Round(number) {
//			function returns the extracted integer part
//			of a decimal number - Math.round is not used
//			since it is only availiable on a Unix platform

	v=number.toString()
	i=v.indexOf(".")
	if ( i==-1 ) {
		return number
	} else {
		if ( i==0 )
			return 0
		else
			return eval(v.substring(0,i))
	}
}



//	Arrays needed for Pascal's triangle function
curvals = new Array()
ProcessingTri=false

function CreateTriangle(dep,fac,pstage) {
//			Procedure to open a new window with pascal's
//			triangle of 'dep' lines deep, coloured according
//			to the factor 'fac'

	if ( pstage==0 ) {
	//		Check for any current triangle processing
		if ( ProcessingTri )
			return

	//		Open up a window
		wstr=((dep*2)+75).toString()
		hstr=((dep*2)+175).toString()
		trianglewindow = window.open("", "", "toolbar=0   , status=0    , menubar=0, scrollbars=0, resizeable=1, width=" + wstr + ", height=" + hstr)
		triwin=trianglewindow.document

	//		Setup window html
		triwin.write("<html><title>Pascals Triangle (Div=" + fac.toString() + ")</title><body bgcolor='#000000' text='#c0c000'><p><br><center>")

	//		Show 'Close window' button
		triwin.write("<p><font size=2>close this window
before opening a new<br><form><input type='button' value=' CLOSE ' onClick='window.close()'></form><p>")

	//		Initialise triangle
		ProcessingTri=true
		TriTimer = window.setTimeout("CreateTriangle("+dep+","+fac+",1)",20)
		return
	}



	if ( pstage>dep ) {
	//		End html text
		triwin.write("</center></body></html>")
		triwin.close()
		ProcessingTri=false
		return
	}
	

	left = 1
	for (j=2; j<=pstage; j++) {
		right = curvals[j]
		curvals[j] = left + right
		left = right
	}
	curvals[pstage] = 1

	//		Produce a row of Pascal's triangle
	for (j=1; j<=pstage; j++) {
		if ( Round(curvals[j]/fac)==(curvals[j]/fac) )
			cps="WhiteDot"
		else
			cps="BlackDot"
		triwin.write("<img src='"+cps+".jpg'>")
	}
	triwin.write("<br>")
	TriTimer = window.setTimeout("CreateTriangle("+dep+","+fac+","+(pstage+1)+")",10)

}

//  end hiding -->
</script>


©1997 Stephen Battey
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