javascript
conversioni e utilità

italiano

english

Tabelle di conversione

Fattori di conversione in PDF

sistema internazionale

multipli e sottomultipli

costanti fondamentali

unità fondamentali e derivate

tavola periodica

calcolatrice scientifica

compatibile IE NE
necessita immagine di fondo, clicca qui

<HEAD>

//<!--

// Javascript scientific calculator  (4 March 1996)

// (C) Copyright Rolf Howarth 1996

// rolf@insect.demon.co.uk

var NDIGITS = 16;

var STACKSIZE = 12;

var value = 0;         // current value in display

var memory = GetCookie("CalcMemory");  // current value in memory

if (!memory) memory = 0;

var level = 0;         // no. of items on stack

var entered = true;    // has value on display been 'entered'?

var decimal = 0;               // multiplier when entering after decimal point

var fixed = 0;         // force trailing zero display when entering decimals

var exponent = false;  // currently entering exponent?

var inverse = false;   // has the INV key been pressed?

if (location.search)

{

// pass in value through command line

value = location.search.substring(1,location.search.length);

}

function stackItem()

{

this.value = 0;

this.op = "";

}

function array(length)

{

this[0] = 0;

for (i=0; i<length; ++i)

{

this[i] = 0;

this[i] = new stackItem();

}

this.length = length;

}

stack = new array(STACKSIZE);

function push(value,op,prec)

{

if (level==STACKSIZE)

return false;

for (i=level;i>0; --i)

{

stack[i].value = stack[i-1].value;

stack[i].op = stack[i-1].op;

stack[i].prec = stack[i-1].prec;

}

stack[0].value = value;

stack[0].op = op;

stack[0].prec = prec;

++level;

return true;

}

function pop()

{

if (level==0)

return false;

for (i=0;i<level; ++i)

{

stack[i].value = stack[i+1].value;

stack[i].op = stack[i+1].op;

stack[i].prec = stack[i+1].prec;

}

--level;

return true;

}

function format(value)

{

var valStr = "" + value;

if (valStr.indexOf("N")>=0 || (value == 2*value && value == 1+value))

return "Error ";

var i = valStr.indexOf("e")

if (i>=0)

{

var expStr = valStr.substring(i+1,valStr.length);

if (i>11) i=11;  // max 11 digits

valStr = valStr.substring(0,i);

if (valStr.indexOf(".")<0) valStr += ".";

valStr += " " + expStr;

}

else

{

var valNeg = false;

if (value < 0)

{ value = -value; valNeg = true; }

var valInt = Math.floor(value);

var valFrac = value - valInt;

var prec = NDIGITS - (""+valInt).length - 1;    // how many digits available after period

if (! entered && fixed>0)

prec = fixed;

var mult = " 1000000000000000000".substring(1,prec+2);

var frac = Math.floor(valFrac * mult + 0.5);

valInt = Math.floor(Math.floor(value * mult + .5) / mult);

if (valNeg)

valStr = "-" + valInt;

else

valStr = "" + valInt;

var fracStr = "00000000000000"+frac;

fracStr = fracStr.substring(fracStr.length-prec, fracStr.length);

i = fracStr.length-1;

if (entered || fixed==0)

{

// remove trailing zeros unless fixed during entry.

while (i>=0 && fracStr.charAt(i)=="0")

--i;

fracStr = fracStr.substring(0,i+1);

}

if (i>=0) valStr += "." + fracStr;

//              document.result.debugField.value = "prec "+prec+", mult "+mult+", frac "+frac;

}

return valStr;

}

function refresh()

{

var display = format(value);

if (exponent)

{

if (expval<0)

display += " " + expval;

else

display += " +" + expval;

}

if (display.indexOf(".")<0 && display != "Error ")

{

if (entered || decimal>0)

display += '.';

else

display += ' ';

}

display = "               " + display;

display = display.substring(display.length-NDIGITS-1,display.length);

document.result.result.value = display;

inverse = false;

}

function clearAll()

{

level = 0;

clear();

}

function clear()

{

exponent = false;

value = 0;

enter();

refresh();

}

function evalx()

{

if (level==0)

return false;

op = stack[0].op;

sval = stack[0].value;

//      alert("eval "+sval+op+value);

if (op == "+")

value = sval + value;

else if (op == '-')

value = sval - value;

else if (op == '*')

value = sval * value;

else if (op == '/')

value = sval / value;

else if (op == 'pow')

value = Math.pow(sval,value);

pop();

if (op=='(')

return false;

return true;

}

function openp()

{

enter();

if (!push(0,'(',0))

{

value = "NAN";

}

refresh();

}

function closep()

{

enter();

while (evalx())

;

refresh();

}

function operator(op)

{

enter();

if (op=='+' || op=='-')

prec = 1;

else if (op=='*' || op=='/')

prec = 2;

else if (op=="pow")

prec = 3;

if (level>0 && prec <= stack[0].prec)

evalx();

if (!push(value,op,prec))

{

value = "NAN";

}

refresh();

}

function enter()

{

if (exponent)

value = value * Math.exp(expval * Math.LN10);

entered = true;

exponent = false;

decimal = 0;

fixed = 0;

}

function equals()

{

enter()

while (level>0)

evalx();

refresh();

}

function digit(n)

{

if (entered)

{

value = 0;

digits = 0;

entered = false;

}

if (n==0 && digits==0)

{

refresh();

return;

}

if (exponent)

{

if (expval<0)

n = -n;

if (digits < 3)

{

expval = expval * 10 + n;

++digits;

refresh();

}

return;

}

if (value<0)

n = -n;

if (digits < NDIGITS-1)

{

++digits;

if (decimal>0)

{

decimal = decimal * 10;

value = value + (n/decimal);

++fixed;

}

else

value = value * 10 + n;

}

refresh();

}

function sign()

{

if (exponent)

expval = -expval;

else

value = -value;

refresh();

}

function period()

{

if (entered)

{

value = 0;

digits = 1;

}

entered = false;

if (decimal == 0)

{

decimal = 1;

}

refresh();

}

function exp()

{

if (entered || exponent)

return;

exponent = true;

expval = 0;

digits = 0;

decimal = 0;

refresh();

}

function inv()

{

inverse = !inverse;

}

function func(f)

{

enter();

if (f=="1/x")

value = 1/value;

else if (f=="swap")

{

var tmp = value;

value = stack[0].value;

stack[0].value = tmp;

}

else if (f=='n!')

{

if (value<0 || value>200 || value != Math.round(value))

value = "NAN";

else

{

var n = 1;

var i;

for (i=1;i<=value;++i)

n *= i;

value = n;

}

else if (f=="MR")

value = memory;

else if (f=="M+")

{

memory += value;

SetCookie("CalcMemory", memory);

}

else if (f=="Min")

{

memory = value;

SetCookie("CalcMemory", memory);

}

else if (inverse)

{

if (f=="sin")

value = Math.asin(value)*180/Math.PI;

else if (f=="cos")

value = Math.acos(value)*180/Math.PI;

else if (f=="tan")

value = Math.atan(value)*180/Math.PI;

else if (f=="log")

value = Math.exp(value * Math.LN10);

else if (f=="log2")

value = Math.exp(value * Math.LN2);

else if (f=="ln")

value = Math.exp(value);

else if (f=="sqrt")

value = value*value;

else if (f=="pi")

value = Math.E;

}

else

{

if (f=="sin")

value = Math.sin(value/180 * Math.PI);

else if (f=="cos")

value = Math.cos(value/180 * Math.PI);

else if (f=="tan")

value = Math.tan(value/180 * Math.PI);

else if (f=="log")

value = Math.log(value)/Math.LN10;

else if (f=="log2")

value = Math.log(value)/Math.LN2;

else if (f=="ln")

value = Math.log(value);

else if (f=="sqrt")

value = Math.sqrt(value);

else if (f=="pi")

value = Math.PI;

}

refresh();

}

function hex()

{

location = "js-hcalc.htm?"+value;

}

/////////////

//  Cookie Functions - Second Helping  (21-Jan-96)

//  Written by:  Bill Dortch, hIdaho Design <bdortch@netw.com>

//  The following functions are released to the public domain.

function getCookieVal (offset) {

var endstr = document.cookie.indexOf (";", offset);

if (endstr == -1)

endstr = document.cookie.length;

return unescape(document.cookie.substring(offset, endstr));

}

function GetCookie (name) {

var arg = name + "=";

var alen = arg.length;

var clen = document.cookie.length;

var i = 0;

while (i < clen) {

var j = i + alen;

if (document.cookie.substring(i, j) == arg)

return getCookieVal (j);

i = document.cookie.indexOf(" ", i) + 1;

if (i == 0) break;

}

return null;

}

//  Function to create or update a cookie.

//    name - String object object containing the cookie name.

//    value - String object containing the cookie value.  May contain

//      any valid string characters.

//    [expires] - Date object containing the expiration data of the cookie.  If

//      omitted or null, expires the cookie at the end of the current session.

//    [path] - String object indicating the path for which the cookie is valid.

//      If omitted or null, uses the path of the calling document.

//    [domain] - String object indicating the domain for which the cookie is

//      valid.  If omitted or null, uses the domain of the calling document.

//    [secure] - Boolean (true/false) value indicating whether cookie transmission

//      requires a secure channel (HTTPS).

function SetCookie (name, value) {

var argv = SetCookie.arguments;

var argc = SetCookie.arguments.length;

var expires = (argc > 2) ? argv[2] : null;

var path = (argc > 3) ? argv[3] : null;

var domain = (argc > 4) ? argv[4] : null;

var secure = (argc > 5) ? argv[5] : false;

document.cookie = name + "=" + escape (value) +

((expires == null) ? "" : ("; expires=" + expires.toGMTString())) +

((path == null) ? "" : ("; path=" + path)) +

((domain == null) ? "" : ("; domain=" + domain)) +

((secure == true) ? "; secure" : "");

}

function DeleteCookie (name) {

var exp = new Date();

exp.setTime (exp.getTime() - 1);  // This cookie is history

var cval = GetCookie (name);

document.cookie = name + "=" + cval + "; expires=" + exp.toGMTString();

}

// End of cookie functions

//////////

// -->

</script>

</HEAD>

</FORM>

</MAP>

</BODY>

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(ver. # 23.03.08 )

javascript conversioni e utilità

calcolatrice scientifica

javascript
conversioni e utilità