Crystal报告用于获取组“最小”和“最大”运行总计的平均值的公式

Question

First question here.

My question is how do I get an average of running total minimums and an average of running total maximums? I'm thinking I will need to use a formula rather than running totals but I don't know what that formula is.

I'm writing a crystal report that gives occurrences of a thing over time. How many times did a thing happen each month for a year grouped by month. Also, how long did it take to happen? Average time, Minimum Time, Maximum Time.

Year     | Month  | How Many | Average? (days) | Minimum Time | Maximum Time

2017

January  | 15      | 5       | 2           | 16          
February | 7       | 4       | 1           | 10      
March    | 20      | 6       | 4           | 12       
Average  | 14      | 5       | 2.33        | 12.66 

I am using a running total in the month groups to get the average, min, and max for each month.

But when I get to the average for all the groups, I want the average for all the minimums and the average for the maximums. I don't want the minimum for the year which would be 1. I could use a running total for that. I want 2.33. Crystal doesn't let me to a running total average on running total minimums.

I hope that makes sense. Thanks in advance for your help.

Answer 1

I would use a Formula Field to create a variable to accumulate values and then a second Formula Field to count the number of times it has accumulated a value. Then you divide the accumulated total by the counter to get your average.

The formula for the accumulator would be...

WhilePrintingRecords;
Shared Numbervar MinsAccumulator := MinsAccumulator + {#Minimum_Time};

The formula for the counter would be...

WhilePrintingRecords;
Shared Numbervar counter = counter + 1;

Do keep in mind though, if the section you use this within is repeated at all, then you will also need a formula field to reset the values of your variables to zero. This would look like this...

WhilePrintingREcords;
Shared Numbervar counter = 0;

Just drop each formula field into the section where you want them to be evaluated and then suppress the fields so they don't display. Then you can create additional formula fields to display the value of the variable you want to use in your report. here is the formula for displaying the variable.

Shared Numbervar counter;
counter;

If you aren't familiar with using variables in Crystal Report just respond back and I can explain them in more detail. They can be a little tricky at first.