Subtracting the lowest n terms from a set

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 14:29:56 +0000

THIS IS FOR THE TI-NSPIRE, NOT THE 83.

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 14:29:38 +0000

The problem I'm having is the "and remove the last two elements" part. I have the randint defined in a variable, not just ans. Ans wouldn't even work because I'm storing it in the middle of a program anyway. I know how to sort the list, but removing more than one element takes some work.

Note: This is on the Ti-Nspire. For some reason, even though it's in the Nspire forum, everyone thinks it's for the Ti-83. If your advice is for the 83, then oh well.

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 12:54:06 +0000

Store the randint into list instead of dealing with ans. then you can use sortA and remove the last two elements

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 10:39:13 +0000

The dim( function only outputs the number of elements, the storing as 3 thing doesn't work. Are you sure that's the right syntax for Ti-Nspire?

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 04:54:55 +0000

You could sort the list from in descending order and delete the last n terms by defining the dimension of the list. Then, you can calculate the average of the dice you want after removing the lowest terms.
For example,

SortD(randInt(1,6,5 3->dim(Ans sum(Ans)/3

Re: Subtracting the lowest n terms from a set

Sat, 27 Sep 2014 00:35:27 +0000

What do you mean use a list? The randint function generates a list already.

Re: Subtracting the lowest n terms from a set

Fri, 26 Sep 2014 23:33:51 +0000

try using a list instead. itll be easier to manipulate

Subtracting the lowest n terms from a set

Fri, 26 Sep 2014 23:06:48 +0000

So I'm doing an informal study lately of probability, specifically dice rolling. I've found that if you roll three dice and add them up, the average is about 10.5. If you roll four dice, ignore the lowest roll, and add up the three highest dice, the average is 12.24. I want to try rolling 5 dice and ignoring the lowest 2, but so far I've been rolling them on the calculator to get the averages. Rolling three dice was easy; I just did a summation of sum(randint(1,6,3)). Four dice was trickier, but then I remembered the min( command, and just did a summation of sum(randint(1,6,4))-min(randint(1,6,4)) (the same randint- I just stored the first one as a variable) and that worked out perfectly. I want to do 5 dice now, and tried using the min( command in weird and roundabout ways, but so far nothing's worked. Any help?

For the record, this stemmed from a conversation with my friend about rolling stats for D&D, in which one of the most common ways is to roll 4 dice and drop the lowest. We want to find the averages for different methods to roll stats.