Re: Exponential Function Programming

in reply to Exponential Function Programming

# exp.

$n = 2;

$e_n = exp($n);
print "e^$n = $e_n\n";

sub my_factorial {
    my $n = shift;
    my $s=1;
    my $r=1;
    while ($s <= $n) {
        $r *= $s;
        $s++;
    }
    if($n == 0) {
        $r=0;
    }
    return $r;
}

sub my_exp_x {
    my $x = shift;
    my $max_iterations = shift;

    my $result = 1 + $x;
    my $i = 2;
    
    while ($i < $max_iterations) {

        $result += ($x ** ($i)) / (my_factorial($i));

        $i++;

    }
    
    return $result;
}

print "test: ", my_exp_x($n,1000);
[download]

Comment on Re: Exponential Function Programming Download Code

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Re^2: Exponential Function Programming by Dominus (Parson) on Nov 23, 2007 at 19:45 UTC
`sub my_factorial { ... if($n == 0) { $r=0; } return $r; }` [download] Your function says that 0 factorial is 0. But it's not; it's 1. -- Mark Dominus Perl Paraphernalia	[reply] [d/l]
Re^3: Exponential Function Programming by blazar (Canon) on Nov 24, 2007 at 13:42 UTC
Perl 6 is very generous in this: `pugs> sub postfix:<!> (Int $n) { [*] 1..$n } undef pugs> say $_! for ^10 1 1 2 6 24 120 720 5040 40320 362880 undef` [download] (I personally believe that I've posted this before here and in different media, but that's jut because it's quite about the only thing I can actually do in pugs ATM.)	[reply] [d/l]
Re^2: Exponential Function Programming by Abulil (Initiate) on Nov 22, 2007 at 15:57 UTC
i got your program but what im looking for is how to do the basic function as it is for example i need to do X to the power of N, then divide it by N factorial and at the end add them all from (1 until the N number i entered) Thanks alot	[reply]
Re^3: Exponential Function Programming by okram (Monk) on Nov 22, 2007 at 16:03 UTC
x to the power of n is done via: `$x ** $n` or `sub x_power_n { my $x = shift; my $n = shift; my $result = $x; my $i = 1; while ($i < $n) { $result *= $x; $i++; } return $result; }` [download] You need to do this, though, "infinite" times, reason why I provided a parameter to "stop" after a certain time.	[reply] [d/l] [select]
Re^4: Exponential Function Programming by ikegami (Patriarch) on Nov 22, 2007 at 19:38 UTC
That only works for integer exponents. The equation in the OP handles real numbers. Using `exp` and `ln`, it's possible to find any exponent.	[reply] [d/l] [select]
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