This was a special request so let me know what other indicators you would like me to write scripts for!
Can you give another look at the S&C article and the code?
Line 23 obvdi = b != 0 ? a / b : 0
should be obvdi = b != 0 ? (1+a) / (1+b) : 0
Line 26 obvdiColor = obvdi > sig ? color.green : obvdi < sig ? color.red : color.black
The interpretation should be sig crosses up .85 Buy sig crosses down .95 Sell, with the possibility to input the boundaries.