# How would I express this scenario Mathematically

• Apr 15th 2012, 06:14 PM
rajeshkhan808
How would I express this scenario Mathematically
Hello , I was hoping the experts here could help me out on this.
Suppose that i have an expression like. (I am simplifying the scenario)
t1+t2+t3+t4+t5+t6
The t in the expression represents time interval. t1 might have some value in seconds and similarly t2 might have some value.
I know the above expression can be expressed as
Attachment 23611
Now is there a way to modify the above expression or another way to express something like "Out of the 6 , only include those t values that have a value greater than 5 seconds"
For example . Suppose - t1=2 sec , t2=8 sec , t3=1 sec, t4=0 sec , t5=10sec , t6=12 sec
So the expression would only be
t2+ t5 + t6

Any suggestions would be appreciated. Thanks
• Apr 16th 2012, 07:39 AM
jsndacruz
Re: How would I express this scenario Mathematically
I'm not exactly sure how to write it, but you might be able to use an indicator function. It could be set up as a binary that would multiply any values less than 5 by zero, so they aren't counted, and any values over 5 by one, so they are included. If you Google around, you might be able to find an example. I can't find one right now.

Do you mind me asking what the broader context of this question is?