Lists

What is the maximum length of a list? May I have 16,000 elements in it?

Can I access an item of a specific index? Say I have a list (or a table) and I want the last item in the list. Is there a way to do this?

Kashi - you can find a certain number in a list like x1[3] will give the 3rd number in the x1 list. 

Can you concatenate lists? For example, if I have a=[1,2,3,4] and b=[5,4,3,2,1] and I want to get c=[1,2,3,4,5,4,3,2,1] can I do something like c=a+b?   

Aran - not currently, but it's on our list!

Can you get multiple entries from an list, like getting entries 2 to 6, but in one thing? If not, how could you get Quartile 1 and Quartile 3 from any given list?

You can try something like this to reference certain elements in a list: https://www.desmos.com/calculator/zcyahozrpb

I made two original equations to go from binary to decimal and decimal to binary. The binary to decimal uses the lists feature in desmos. I was wondering if there was any way that I could make a number into a list so that I could just type in the number in a function I guess and use that list instead of putting a comma after every single digit in a 20 digits long binary string.

Bryan Garcia, The trick is to use an intermediary list. I made an example that will convert a decimal whole number to a list of digits. You can modify it as needed. https://www.desmos.com/calculator/7dsepfo2pe

MrYurihi redstone, You can use the quantile function in the stats menu. To get Q1 and Q3 of a list A you would use the commands quantile(A,.25) and quantile(A,.75). You can even use the quantile function to sort a list. The worksheet https://www.desmos.com/calculator/rfgwycggun shows an example of a sorted list along with a method to concatenate lists or to get a sublist, 

Aran Glancy,

see here for concatenating lists

I have an equation with 2 parameters (say A and B) in it, and I want to show all the graphs with all combinations of A and B at integers from 1 to 10. If I put A=[1,...,10] and then B=[1,...,10], I only get the graphs for A ranging from 1 to 10 with B fixed at 1. How do I show combinations of choices for the two parameters?

Joe. There are currently no methods for iterating over two lists as you requested. Instead, you could make two lists of length 100 to cover all the ordered pairs. The worksheet https://www.desmos.com/calculator/cg2i9poeub has an example showing how that might be done.

Okay thanks. I had already done the thing you suggested.

How do i find quartiles on desmos?

Bakerjr2159 To get quartiles define a list "L=[1,2,3,4,5]" (or table of values with header "L") and enter quantile(L,0.25) to get the first quartile.

Abotting213 - No, you can have up to 10000 entries.

BTY: if you try to make a list like this, with more than 10000 entries, desmos won't do anything until you reload.

Can I set lists to be unbounded between them? If I create a function with two variables and I set the variable A as [0,1,...,9] and B as [0,1,...,9] automatically the result is the combination of the first objects, second objects, third objects and so on.... but I would like the whole possible combination between them Is it possile?

Maxim, there is no way to nest lists, unfortunately. One possible way to get all of the ordered pairs (0,0) through (9,9) is to make use of another list like this link: https://www.desmos.com/calculator/odm1auohqk

Is there a way to find the sum of a list, like [0,1,2,3,4,5] would sum to 15?

total([0,1,2,3,4,5]) will give you the sum of the list.

Kashi Yamagato: if you want the last element in a list:

L = [0,1,5,9]

S = length(L)

L[S] gives "9", L[S-1] gives "5", and so on.

Is there any way to reverse a list? Everything I try only sums a list's elements instead of reversing it.

The list reversal question is a good one. I can't think of any satisfying way to do it. You could create an intermediary list and use summation like at https://www.desmos.com/calculator/yhrhf93c6x but it's not particularly pleasing.

Can I apply a rule to a list for easy edits of equations?

Ex. X=[1,2,3,4] & Y=2[X]