Roots of a function: Difference between revisions

}

</pre>

=={{header|Perl}}==

<pre>sub f

{

my $x = shift;

return ($x * $x * $x - 3*$x*$x + 2*$x);

}

my $step = 0.001; # Smaller step values produce more accurate and precise results

my $start = -1;

my $stop = 3;

my $value = &f($start);

my $sign = $value > 0;

# Check for root at start

print "Root found at $start\n" if ( 0 == $value );

for( my $x = $start + $step;

$x <= $stop;

$x += $step )

{

$value = &f($x);

if ( 0 == $value )

{

# We hit a root

print "Root found at $x\n";

}

elsif ( ( $value > 0 ) != $sign )

{

# We passed a root

print "Root found near $x\n";

}

# Update our sign

$sign = ( $value > 0 );