Format Decimal

Function: string FormatDecimal(float number, integer precision);

Formats a float value to a fixed precision ie. for display purposes

Returns a string that comprises the number truncated and rounded to the given precision.

• float	number	–	any valid float, positive or negative
• integer	precision	–	precision of result. Positive values truncate fraction, negative values truncate integer part of number

Specification

string FormatDecimal (float number, integer precision)
{    
    float roundingValue = llPow(10, -precision)*0.5;
    float rounded;
    if (number < 0) rounded = number - roundingValue;
    else            rounded = number + roundingValue;
    
    if (precision < 1) // Rounding integer value
    {
        integer intRounding = (integer)llPow(10, -precision);
        rounded = (integer)rounded/intRounding*intRounding;
        precision = -1; // Don't truncate integer value
    }
    
    string strNumber = (string)rounded;
    return llGetSubString(strNumber, 0, llSubStringIndex(strNumber, ".") + precision);
}

Examples:
FormatDecimal(123.456, 2); // Result: 123.46
FormatDecimal(-123.456, 2); // Result: -123.46
FormatDecimal(123.456, 0); // Result: 123
FormatDecimal(-123.456, -2); // Result: -100

Caveats

Maximum value is restricted to integer range, that is -2,147,483,648 to +2,147,483,647

Example

Trivial example to listen to any chat from the object owner for number,precision values and respond formatted value.

string FormatDecimal (float number, integer precision)
{    
    float roundingValue = llPow(10, -precision)*0.5;
    float rounded;
    if (number < 0) rounded = number - roundingValue;
    else            rounded = number + roundingValue;
    
    if (precision < 1) // Rounding integer value
    {
        integer intRounding = (integer)llPow(10, -precision);
        rounded = (integer)rounded/intRounding*intRounding;
        precision = -1; // Don't truncate integer value
    }
    
    string strNumber = (string)rounded;
    return llGetSubString(strNumber, 0, llSubStringIndex(strNumber, ".") + precision);
}

default
{
    state_entry()
    {
        llOwnerSay("Enter: [number,precision]");
        llListen(0, "", llGetOwner(), "");
    }

    listen(integer _chan, string _str, key _id, string _msg)
    {
        list values=llCSV2List(_msg);
        float number = llList2Float(values,0);
        integer decimals = llList2Integer(values,1);
        llOwnerSay("Number " + (string)number + " is formatted " + FormatDecimal(number, decimals));
    }
}