JavaScript - Help With Math Functions..looping Them

hey. im working on a facebook app..
this is what i got so far.
PHP Code:
<script language="JavaScript">
<!--

var theImages = new Array() 


theImages[0] = "http://img688.imageshack.us/img688/4787/logo1tq.jpg"
theImages[1] = "http://img641.imageshack.us/img641/8292/logo2yex.jpg"
theImages[2] = "http://img864.imageshack.us/img864/4097/logo3ik.jpg"
theImages[3] = "http://img543.imageshack.us/img543/9046/logo4pu.jpg"
theImages[4] = "http://img21.imageshack.us/img21/2567/logo5q.jpg"
theImages[5] = "http://img842.imageshack.us/img842/696/logo6o.jpg"
theImages[6] = "http://img85.imageshack.us/img85/7831/logo7k.jpg"


var j = 0
var p = theImages.length;

var preBuffer = new Array()
for (i = 0; i < p; i++){
   preBuffer[i] = new Image()
   preBuffer[i].src = theImages[i]
}

var whichImage = Math.round(Math.random()*(p-1));
function showImage(){
document.write('<img src="'+theImages[whichImage]+'">');
}

//-->
</script>


<script language="JavaScript">
<!--

showImage();
//-->
</script> 


now i want that the app posts the random image automaticlly to the useres timeline.. for example: if the random image is theImages [3] then it should post the image theimage [3] to the users timeline.. i see alot of facebook apps doing this.. thanks in advance

How can you add/substract two numbers in javascript if they are written out as words such as one|two|three|four|five|six|seven|eight|nine|ten.

Code:

if ((word[0].match(/one|two|three|4|five|six|seven|eight|nine|ten/)) && (word[1].match(/plus|add/)) && (word[2].match(/one|two|three|4|five|six|seven|eight|nine|ten/))) {

document.result.result.value = "The answer is ?"; 
return true;}

I'm making a 3d pie chart. I have the points and the correct method to fill everything but when the slice rotates I want to make the outer edge filled, but in order to do that I have to figure out what math I use to find the leading edge.
I made a picture to hopefully explin what I need to find. I figure it might be the tangent but I was hoping someone smarter than I could send me in the right direction. I just need someone to help me pinpoint my next step.

Right now the rendering uses start and end angles to first make the top and bottom sections, fills them and then it makes an arc along the top of the slice from start to end then from end to start on the bottom slice and completes the polygon by going back the first point in the arc.

I need to make two separate polygons if the end or start are further from the center than the( tangent?) point. Need some advice.

Hope someone has an idea.

I'm a student learning javascript, I'm having a very basic problem. I have to write a script that outputs XHTML text that keeps displaying in the browser window that multiples of the integer 2, namely 2, 4, 8, 16, 32, 64, etc.

This is the code i have,

Code:

<!--
        var product=2; 

	    while {	
		product =2*product; 
	     }
		
             document.writeln( +product+ );
// -->

And it pretty much does nothing. Help would be much appreciated

Dave

Just started to learn java & came up with the following, but can't get the math.round to work. Anyone able to tell me where I'm going wrong please ???

<p>
<script type="text/javascript">// <![CDATA[
var metrics = {
"mm" : 1,
"cm" : 10,
"m" : 1000,
"inch" : 25.4,
"foot" : 304.8
};


function roundNumber(rnum, rlength) { // Arguments: number to round, number of decimal places
var newnumber = Math.round(rnum*Math.pow(10,rlength))/Math.pow(10,rlength);
document.roundform.numberfield.value = parseFloat(newnumber); // Output the result to the form field (change for your purposes)
}



function roundme(len, wid, sq){
math.round.len;
wid = math.round(wid);
sq = math.round(sq);
alert(len);

};

function roundNumber(rnum, rlength) { // Arguments: number to round, number of decimal places
var newnumber = Math.round(rnum*Math.pow(10,rlength))/Math.pow(10,rlength);
document.roundform.numberfield.value = parseFloat(newnumber); // Output the result to the form field (change for your purposes)
};

function changeme(id, action) {

var val = document.getElementById("sizegroup");
if (val.style.display == 'none') {
val.style.display = 'block'
} else {
val.style.display = 'none'
}

};


function convert(num, dec){
var val = document.getElementById("boxa").value;
var val2 = document.getElementById("boxb").value;
if(isNaN(val)){return val};
if(isNaN(val2)){return val2};
document.getElementById("boxc").value = val *
metrics[document.getElementById("choice1").value]/
metrics[document.getElementById("choice3").value];

metrics[document.getElementById("choice1").value]/
metrics[document.getElementById("choice3").value];

document.getElementById("boxd").value = val2 *
metrics[document.getElementById("choice2").value]/
metrics[document.getElementById("choice4").value];


document.getElementById("sqmtrs").value = document.getElementById("boxc").value * document.getElementById("boxd").value ;

document.getElementById("boxc").value = math.round(document.getElementById("boxc").value);


};


var interval = null;
function watchChanges(){
interval == null ? setInterval("convert()", 500) :
clearInterval(interval);

}
// ]]></script>
</p>
<p>Length in imperial-metric / Width in imperial-metric</p>
<div><input id="boxa" style="width: 40px;" onfocus="watchChanges()" onblur="watchChanges()" type="text" /><select id="choice1" onchange="convert();"> <option value="mm">millimeters</option> <option value="cm">centimeters</option> <option value="m">metres</option> <option selected="selected" value="foot">feet</option> <option value="inch">inches</option> </select>

<input id="boxb" style="width: 40px;" onfocus="watchChanges()" onblur="watchChanges()" type="text" /><select id="choice2" onchange="convert()"> <option value="mm">millimeters</option> <option value="cm">centimeters</option> <option value="m">metres</option> <option selected="selected" value="foot">feet</option> <option value="inch">inches</option> </select></div>

<div><input id="boxc" style="width: 40px;" type="text" disabled="disabled" /><select id="choice3" onchange="convert()"> <option value="mm">millimeters</option> <option value="cm">centimeters</option> <option selected="selected" value="m">metres</option> <option value="foot">feet</option> <option value="inch">inches</option> </select>

<input id="boxd" style="width: 40px;" type="text" disabled="disabled" /><select id="choice4" onchange="convert()"> <option value="mm">millimeters</option> <option value="cm">centimeters</option> <option selected="selected" value="m">metres</option> <option value="foot">feet</option> <option value="inch">inches</option> </select></div>
<p>&nbsp;</p>
<div>Total sq metres : <input id="sqmtrs" style="width: 40px;" type="text" value="" disabled="disabled" /></div>
<p>&nbsp;</p>
<div class="label">Please round up to half a metre when choosing</div>
<table border="0" cellspacing="0" cellpadding="5">
<tbody>
<tr>
<td>Round:</td>
<td><input type="text" name="numberfield" value="" /> to <input type="text" name="decimalfield" value="2" size="3" /> decimal places</td>
</tr>
<tr>
<td>Result:</td>
<td><input type="text" name="roundedfield" value="" /> <input onclick="roundNumber(numberfield.value, decimalfield.value);" type="button" value="Calculate" /></td>
</tr>
</tbody>
</table>

Either I made an uh-oh, or there is a serious problem with Javscripts math functions. Math.sin(x) returns the sine of x in radians. Last time I checked, the sine of pi radians is 0, but in javascript:
Code:

Math.sin(Math.PI) // returns 1.2246467991473532e-16

Any idea why?

Julian

ok so heres where I stand, I don't know too much about javascript. Just enough to get me by. I am a PHP developer, I know how to do this in PHP but the client insists on doing it through javascript.

Basically there are 3 different form values that determine the Premium Death Benefit Ratio.

This is the formula the client wants:
Premium to Death Benefit Ratio % (Created by formula = Annual (Level) Premium Amount (Divided by) Death Benefit Amount (equals a percentage) That percentage multiplied by Life Expectancy

The 3 form values in the formula would be Annual Premium Amount (fypremium), Death Benefit Amount (dbp), Life Expectancy (average_le)

I was messing around with javascript trying to figure it out and I have gotten no where since I am not used to writing formulas in JS. Anyways here is what I have so far:

Code:

function calculateLE(inputFieldId1, inputFieldId2, inputFieldId3, outputFieldId){
	var DBR;
	
	var input = document.getElementById(inputFieldId).value;
	
	APA = document.getElementById(fypremium).value;
	DBA = document.getElementById(dbp).value;
	LE  = document.getElementById(average_le).value;
	
	formula = document.getElementById(fypremium).value / document.getElementById(dbp).value = formula3;
	formula2 = document.getElementById(average_le).value * formula3;
	
	if { APA = "" } {
		document.getElementById(outputFieldId).value = "Error getting Annual Premium Amount";
	}
	else if { DBA = "" } {
		document.getElementById(outputFieldId).value = "Error getting Death Benefit Amount";
	}
	else if { LE = "" } {
		document.getElementById(outputFieldId).value = "Error getting Life Expectancy";
	}
	else {
		document.getElementById(outputFieldId).value = formula3;
	}
}

Now I honestly have no clue if I am on the right track but what i've found on the net hasnt really pointed me in the right direction

Here is the form values.

Code:

<input type="text" name="fypremium" id="fypremium" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">
<input type="text" name="dbp" id="dbp" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">
<input type="text" name="average_le" id="average_le" onblur="calculateLE('fypremium', 'dbp', 'average_le', 'premium_dbr')">

In a nut shell the values for the 3 inputs stated above will determine premium_dbr's value.

fypremium / dbp = percentage;
average_le * percentage = DBR (death benefit ratio);

If someone could point me in the right direction to finishing this id be very greatful.

I am at a lost, new to JavaScript and not sure why I am getting Nan

Code:

<script type="text/javascript">
    
    var num1;
    var num2;
    var num3;
    var ave_num=Math.round((num1 + num2 + num3) / 3);
    
    
//follow prompts to enter numbers and print average

    </script>

Hi. I'm in JS kindergarten.

I have a form with a field that asks for a full year. If the year is greater than 20 years ago, I'd like additional form fields to be revealed. If the year is equal to or less than 20 years ago, it will not reveal the fields. (And it should be based on getFullYear(), so I don't have to update the script every year, yeah?)

I figured out how to script onclick functions and some basic .value == functions in order to show/hide just about every type of form field. So I don't need that info. But I'm unsure of how to calculate the value. I'd be interested to see your solutions. No rush. Thanks in advance.

Code:

<script type="text/javascript">
function countItDown(){
	var current=parseFloat(document.getElementById("currentsecondscount").value);
	var seconds=current;
	document.getElementById("debug").innerHTML="S "+current;
	var minutes=Math.floor(seconds/60);
	document.getElementById("debug").innerHTML+="<br>M "+minutes;
	var hours=Math.floor(minutes/60);
	document.getElementById("debug").innerHTML+="<br>H "+hours;
	var days=Math.floor(hours/24);
	document.getElementById("debug").innerHTML+="<br>D "+days;
	var remainingseconds=seconds-(minutes*60);
	document.getElementById("debug").innerHTML+="<br>RS "+remainingseconds;
	var remainingminutes=minutes-(hours*60);
	document.getElementById("debug").innerHTML+="<br>RM "+remainingminutes;
	var remaininghours=hours-(days*24);
	document.getElementById("debug").innerHTML+="<br>RH "+remaininghours;
	
	if(days<10){ days="0"+days; }
	if(remaininghours<10){ remaininghours="0"+remaininghours;}
	if(remainingminutes<10){ remainingminutes="0"+remainingminutes;}
	if(remainingseconds<10){ remainingseconds="0"+remainingseconds;}
	
	document.getElementById("days").innerHTML=days;
	document.getElementById("hours").innerHTML=remaininghours;
	document.getElementById("minutes").innerHTML=remainingminutes;
	document.getElementById("seconds").innerHTML=remainingseconds;
	document.getElementById("currentsecondscount").value=(current-1);
}
</script>
.......
<input type="hidden" id="currentsecondscount" value="<?=$seconds;?>" />
.......

Chrome/IE/etc on Left... FF 3.6.3 [windows] on Right


im not sure why Firefox is doing this. it seems to work fine on Firefox 3.6.3 for Mac...

Hi. I am new to javascript programming so please go easy on me. I am creating a site for a flooring store and need to include a price calculator/estimator.
What I need to do is allow the visitor to input the room size (length x width) and choose a flooring material from a pulldown list, and receive a price.
The pulldown list would have flooring materials such as carpet, tile, wood, etc and each of these would have a fixed dollar amount associated with them (which would be hidden).
So basically it is just a script that would multiply 3 numbers, with two of the numbers being input by the visitor, and th tird being selected from the pulldown.
Can someone please educate me on how to do this?

i had to create a function to calculate percentage and round to integer

need 2 parameters of item and sum
function will return value of item variable divide the sum by 100 and round to nearest integer

using Math.round

this is my code that i came up with

Code:

function calcPercent(item,sum){ // script element to calculate the percentage which is rounded to the nearest integer
     var items = Math.round( (item/sum)*100); // script element to get the percentage
return items;
}
     calcPercent(1, 3);

Does this make sense?
thanks

Hi. I am new to javascript programming so please go easy on me.
I am creating a website for a flooring store and need to include a price calculator/estimator.
What I need to do is allow the visitor to input the room size (length x width) and choose a flooring material from a pulldown list, and receive a price.
The pulldown list would have flooring materials such as carpet, tile, wood, etc and each of these would have a fixed dollar amount associated with them (which would be hidden).

So basically it is just a script that would multiply 3 numbers, with two of the numbers being input by the visitor, and the third being selected from the pulldown.

Can this be done with Javascript, and can someone please educate me on how to do this?

I have this simple manual photo slide show. It shows four photos and when you click the next button and it moves one photo over and one photo back for the previous button. I have to moving by changing the CSS property of 'left' by 195 pixels each move. So for it to move next it will subtract 195 pixels from the left property and for moving back it add 195 pixels to the left property. I have the code setup so when you click it changes the property of left to either -195 or 195 pixels but I need it so it actually does the math, not just give it a set value. But I don't know how to do that.

Code:

function MM_changeProp(objId,x,theProp,theValue) { //v9.0
  var obj = null; with (document){ if (getElementById)
  obj = getElementById(objId); }
  if (obj){
    if (theValue == true || theValue == false)
      eval("obj.style."+theProp+"="+theValue);
    else eval("obj.style."+theProp+"='"+theValue+"'");
  }
}
function nextPhoto() {	
	MM_changeProp('fanThumbWrapOne','','left','-195px','DIV')
}
function prevPhoto() {	
	MM_changeProp('fanThumbWrapOne','','left','195px','DIV')
}

so where you see -195px and 195px in the functions for nextPhoto and prevPhoto I need those to actually be functions where it subtracts 195px or adds 195px.

i have a program where a user enters a temperature in farenheit and the program converts it to celcius.

below is my code:

Code:

<html>
<head>
<title>JavaScript Assignment 4 Part 1</title>



</head>
<body>
<h2>Welcome to the Temperature Calculator!!</h2>

<script type="text/javascript">

var fTemp;
var number1;
var cTemp;



fTemp = window.prompt( "Please enter temperature in Farenheit:", "0" );

number1 = parseInt( fTemp );

cTemp = (5/9) * (number1 - 32);




document.writeln("The corresponding temperature in Celcius is: " + cTemp);


</script>


</body>
</html>

what i cant figure out is how to round off the temperature in celcius so that it doesnt display something like 26.666666666667
i tried putting math.round in
"cTemp = (5/9) * (number1 - 32);"

but when i do my program doesnt work
any advice on how to go about doing this?
thanks