modified something.
#!/usr/bin/perl
@R=(0,0.5,1,1.1,1.2,1.3,1.5,1.6,1.8,2,2.2,2.4,2.7,3,3.3,3.6,3.9,4.3,4.7,5.1,5.6,6.2,6.8,7.5,8.2,9.1,10,11,12,13,15,16,18,20,22,24,27,30,33,36,39,43,47,51,56,62,68,75);
foreach $R1 (@R)
{
foreach $R2 (@R)
{
foreach $R3 (@R)
{
foreach $R4 (@R)
{
if ( $R1 != 0 ) { $X1 = 1/$R1 } else { $X1 = 0 };
if ( $R2 != 0 ) { $X2 = 1/$R2 } else { $X2 = 0 };
if ( $R3 != 0 ) { $X3 = 1/$R3 } else { $X3 = 0 };
if ( $R4 != 0 ) { $X4 = 1/$R4 } else { $X4 = 0 };
next if ( $X1 + $X2 + $X3 + $X4 == 0 );
$RT = 1 / ( $X1 + $X2 + $X3 + $X4 );
$RT = substr( $RT , 0 , 6 );
print "$R1 $R2 $R3 $R4 = $RTn" if ( $RT >= $ARGV[0] and $RT <= $ARGV[0] + 0.0005 );
print "$R1 $R2 $R3 $R4 = $RTn" if ( $RT <= $ARGV[0] and $RT >= $ARGV[0] - 0.0005 );
}
}
}
}
exit;