Possibly the other way around might be easier to understand?
number_of_days in period / number_of_appointments_in_period

gives the number of days between appointments. (I find users have an easier time with integers than fractions).

/ Jim

>How about a daily weighted frequency:
>number_of_appointments_in_period / number_of_days in period
>So, if a patient comes in 3 times in 90 days.
>daily weight would be 3 / 90, or .033
>
>>Given a date parameter with 3 consecutive months(01Jan05 to 31March05), I need to find the appointment average frequency of a patient in this range. Patient can come in once a week or once a month or basically no pattern at all within that range. Assuming that I have 2 patient(A & B), here's my pattern:
>> A: 12Jan
>> 15Feb
>> 01Mar
>> 14Mar
>> B:04Jan 01Feb 01Mar
>> 11Jan 08Feb 03Mar
>> 18Jan 10Feb 08Mar
>> 19Jan 15Feb 15Mar
>> 21Jan 17Feb 17Mar
>> 25Jan 22Feb
>> 27Jan 24Feb
>>
>> Basic user parameter will consist of:
>> Date range - 01Jan05 to 31Mar05
>> Freqeuncy type - Weekly/Monthly
>>
>>So basically, Patient A has an average of 1/month and Patient B has 6/Month or 2/week. My problem here is what to use for the average frequency criteria (Week or Month). How should i handle the frequency type tp use (Month/Week)? Considering the scenario above, is it safe for me to say that if a patient that has less than 4 average frequency visit per month, I can make this to a weekly, if the user wanted the frequency per week.
>>Otherwise if its just less than 4 per month, my criteria will be a monthly frequency automatically, basically forcing it to be a Monthly type. Any ideas how or at least a better way of doing this? TIA!