FileMaker Pro Custom Functions

/*GetAsArabic( romanNumber ) returns the arabic number equivalent to romanNumber [text]. It will return correct values for both correctly and incorrectly formed roman numberals, and ignore all characters other than “i”, “v”, “x”, “l”, “c”, “d”, and “m”.*/ Let( roman = Lower( romanNumber); //normalize romanNumber to lowercase //tally values for letters (PatternCount( roman, "i") * 1) + (PatternCount( roman, "v") * 5) + (PatternCount( roman, "x") * 10) + (PatternCount( roman, "l") * 50) + (PatternCount( roman, "c") * 100) + (PatternCount( roman, "d") * 500) + (PatternCount( roman, "m") * 1000) - //subtract for complex values (PatternCount( roman, "iv") * 2) - //(i+v)-iv=(1+5)-4=2 (PatternCount( roman, "ix") * 2) - //(i+x)-ix=(1+10)-9=2 (PatternCount( roman, "xl") * 20) - //(x+l)-xl=(10+50)-40=20 (PatternCount( roman, "xc") * 20) - //(x+c)-xc=(10+100)-90=20 (PatternCount( roman, "cd") * 200) - //(c+d)-cd=(100+500)-(400)=200 (PatternCount( roman, "cm") * 200) //(c+m)-cm=(100+1000)-900=200 ) //end Let()
 Then copy & paste into FileMaker Advanced's Edit Custom Function window.