Tierprice decimals display

Question

I am trying to display all prices with 4 decimals (i know a little bit weird but the customer demanded this). I have overwritten Mage/Core/Store, changed the currency.php precision in the Zend lib and adjusted Mage_Directory_Model_Currency.

In the backend, all my prices are displayed correctly but in the frontend i receive a price rounded to 2 decimals followed by 00. Especially the tier price is very crucial.

Since i dont have any knowledge in pricing i have tried some tutorials on Magento Forum with no success. I also tried 2 extensions with no luck.

Any help?

Answer 1

I decided not to do it and adviced the customer to refrain from pushing it because I could not get any exact results. As mentioned in the comments:

4 decimal precision is inherently imprecise in Magento.

Answer 2

I think you'll find what you need in the format method inside app/code/core/Mage/Directory/Model/Currency.php.

/**
 * Format price to currency format
 *
 * @param   double $price
 * @param   bool $includeContainer
 * @return  string
 */
public function format($price, $options=array(), $includeContainer = true, $addBrackets = false)
{
    return $this->formatPrecision($price, 2, $options, $includeContainer, $addBrackets);
}

Answer 3

I had to completely rewrite my template's price.phtml anyway, and I used
<?php printf("$%.2f", $_finalPrice) ?> so you could do the same but with %.4f

Also, if needing to perform comparisons on floats, I recommend:
if( abs($_price1 - $_price2) < .0001 ) instead of if($_price1 == $_price2)

Sometimes, php's type flexibility induces unexpected errors, so explicit casting to your desired data type is often needed: $margin=(float)1-$margin; I have gotten to where I don't even try to stack multiple math operations into one line of code.