function calculatetime(){
var form = document.timeform;
// get conversion factors from selected options
var i = form.distunits.selectedIndex;
var distunitsvalue = form.distunits.options[i].value;
var j = form.speedunits.selectedIndex;
var speedunitsvalue = form.speedunits.options[j].value;
// calculate time in seconds
var d = form.distvalue.value;
if (isblank(d)) d = '0';
else
d = parseFloat(d);
var s = form.speedvalue.value;
if (isblank(s)) s = '0';
else
s = parseFloat(s);
var t = (d * distunitsvalue) / (s * speedunitsvalue);
// convert to hours, minutes, seconds
form.hourvalue.value = Math.floor(t / 3600);
t = t - (form.hourvalue.value * 3600);
form.minutevalue.value = Math.floor(t / 60);
form.secondvalue.value = Math.floor(t - (form.minutevalue.value * 60));
return true;
}
function calculatedistance(){
var form = document.distform;
// get conversion factors from selected options
var i = form.distunits.selectedIndex;
var distunitsvalue = form.distunits.options[i].value;
var j = form.speedunits.selectedIndex;
var speedunitsvalue = form.speedunits.options[j].value;
var h = form.hourvalue.value;
if (isblank(h)) h = '0';
else
h = parseFloat(h);
var m = form.minutevalue.value;
if (isblank(m)) m = '0';
else
m = parseFloat(m);
var s = form.secondvalue.value;
if (isblank(s)) s = '0';
else
s = parseFloat(s);
var sp = form.speedvalue.value;
if (isblank(sp)) sp = '0';
else
sp = parseFloat(sp);
// convert time to seconds
var temp = (h * 3600) + (m * 60) + s;
// calculated distance
form.distvalue.value = roundoff(((sp * speedunitsvalue) * temp) / distunitsvalue, 5);
return true;
}
function calculatespeed(){
var form = document.speedform;
// get conversion factors from selected options
var i = form.distunits.selectedIndex;
var distunitsvalue = form.distunits.options[i].value;
var j = form.speedunits.selectedIndex;
var speedunitsvalue = form.speedunits.options[j].value;
var h = form.hourvalue.value;
if (isblank(h)) h = '0';
else
h = parseFloat(h);
var m = form.minutevalue.value;
if (isblank(m)) m = '0';
else
m = parseFloat(m);
var s = form.secondvalue.value;
if (isblank(s)) s = '0';
else
s = parseFloat(s);
var d = form.distvalue.value;
if (isblank(d)) d = '0';
else
d = parseFloat(d);
// convert time to seconds
var temp = (h * 3600) + (m * 60) + s;
// calculate speed
form.speedvalue.value = roundoff(((d * distunitsvalue) / (temp * speedunitsvalue)), 5);
return true;
}
function roundoff(x,y){ //round off x to y decimal places
x = parseFloat(x);
y = parseFloat(y);
x = Math.round(x * Math.pow(10,y))/Math.pow(10,y);
return x;
}
function isblank(s)
{
for(var i = 0; i < s.length; i++) {
var c = s.charAt(i);
if ((c != ' ') && (c != '\n') && (c != '\t')) return false;
}
return true;
}
//-->
DMD - Calculate Time, Distance and Speed
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