Randbetween of a list

J_jvs · 04-10-2020 08:35 AM

Hi Team,
how can i do a randbetween of a list? its possible?
and then eliminate this number of the list.
br

WillowMobileSys

You can use the function like this:

RANDBETWEEN(1, COUNT([List]))

Then use the INDEX function to get that item in the list:

INDEX([List], RANDBETWEEN(1, COUNT([List])))

Then you can subtract it from the original list but the item has to be in LIST form

[List] - LIST(INDEX([List], RANDBETWEEN(1, COUNT([List]))))

NOTE: I have not tested this

Suvrutt_Gurjar

@WillowMobileSystems,

Good one. Nice practical solution.

J_jvs

Hi John Baer,
thks but,
whats about this error?
br

WillowMobileSys

[List] was my generic reference to some list variable. You need to replace it with whatever your list is. It could be a SELECT() function or a column of some LIST type like EnumList.

J_jvs

Hi John,
I don’t know where I’m wrong
i’m attaching you 4 results.
and I dont know how to use index option?
br

WillowMobileSys

In your examples, for each of the columns A, B, C and D, it seems you are reusing the RANDBETWEEN function each time which means it re-generating a new random number in each column.

You need to use the saved [randomNumber] value in columns C and D. For example in Column C the expression should be

INDEX([initialList], [randomNumber])

The expression in Column D should be:

[initialList] - LIST(INDEX([initialList], [randomNumber]))

WillowMobileSys

I quickly implemented this in a tester app. It appears to be working well. Note how it works when the list is not in sorted order.

J_jvs

thks a lot John for your help,
its running.

J_jvs

Hi John,
and now, how I can not repeat randomNumber? its possible?
My initial idea was to use [newList] as [initialList] but its impossible, its a circular definition and not works.

br

Steve

What are you trying to accomplish here? Something like shuffle play a playlist?

J_jvs

Hi Steve,
I have 10 differents cards and 2 players, and i want to deal the cards.

Steve

Suppose a Cards table has the columns: Suit, Value, and ID (the combination of the suit and value); and 52 rows for a common deck of cards. To deal player 1, set Player 1 Hand to the output of:

TOP(ORDERBY(Cards[ID], RANDBETWEEN(1, 999999)), 5)

and to deal player 2, set Player 2 Hand to the output of:

TOP(ORDERBY((Cards[ID] - [Player 1 Hand]), RANDBETWEEN(1, 999999)), 5)

See also:

J_jvs

Hi Steave,
why using “TOP(ORDERBY(Cards[ID], RANDBETWEEN(1, 999999)), 5)”,
appears this message “ORDERBY has invalid inputs”?

br

Steve

Did you replace Cards[ID] with the appropriate column specification for your app?

J_jvs

Yes I did.
top(orderby(game[card],RANDBETWEEN(1, 999999)), 5)

Steve

The the Card column the key column of the Game table?

Grant_Stead

smart solution

J_jvs

No Steve, key column is “row_number”.
To check it quickly i simplified situation using only one player.

Steve

Try:

top(orderby(game[_rownumber],RANDBETWEEN(1, 999999)), 5)

J_jvs

[card] as enum list type?

Marc_Dillon

This looks interesting. I don’t understand how passing a number as the 2nd argument to ORDERBY() works though? Is this an un-documented feature?

Steve

It’s documented:

J_jvs

J_jvs

Hi Steve,
the result is ok for you? it seems ir running,
but for my use is not ok , i need another column with only the new card.

I attaches you an example [onlyCard].

br