Home |
Search |
Today's Posts |
|
#1
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
Hi there
Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#2
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
You may want to visit J.E. McGimpsey's site and grab a copy of his =RandInt()
function. http://www.mcgimpsey.com/excel/udfs/randint.html If you're new to macros: Debra Dalgleish has some notes how to implement macros he http://www.contextures.com/xlvba01.html David McRitchie has an intro to macros: http://www.mvps.org/dmcritchie/excel/getstarted.htm Ron de Bruin's intro to macros: http://www.rondebruin.nl/code.htm (General, Regular and Standard modules all describe the same thing.) mike_vr wrote: Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike -- Dave Peterson |
#3
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
mike_vr wrote on Tue, 9 Mar 2010 09:19:01 -0800:
Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Technically, if you do not allow duplication you don't truly have random numbers. However, there are sites that will produce both duplicated and unduplicated "random" digits, for example, http://stattrek.com/Tables/Random.aspx These could be put in a column and selected sequentially. -- James Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not |
#4
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
"James Silverton" wrote:
Technically, if you do not allow duplication you don't truly have random numbers. So by your definition, it is impossible to choose 6 people "at random" from a group of 49. Wrong! There is random selection "with replacement" and "without replacement". ----- original message ----- "James Silverton" wrote in message ... mike_vr wrote on Tue, 9 Mar 2010 09:19:01 -0800: Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Technically, if you do not allow duplication you don't truly have random numbers. However, there are sites that will produce both duplicated and unduplicated "random" digits, for example, http://stattrek.com/Tables/Random.aspx These could be put in a column and selected sequentially. -- James Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not |
#5
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
Joe wrote on Tue, 9 Mar 2010 09:54:20 -0800:
"James Silverton" wrote: Technically, if you do not allow duplication you don't truly have random numbers. So by your definition, it is impossible to choose 6 people "at random" from a group of 49. Wrong! There is random selection "with replacement" and "without replacement". ----- original message ----- "James Silverton" wrote in message ... mike_vr wrote on Tue, 9 Mar 2010 09:19:01 -0800: Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Technically, if you do not allow duplication you don't truly have random numbers. However, there are sites that will produce both duplicated and unduplicated "random" digits, for example, http://stattrek.com/Tables/Random.aspx These could be put in a column and selected sequentially. So by your definition, it is impossible to choose 6 people "at random" from a group of 49. Wrong! There is random selection "with replacement" and "without replacement". My aside was somewhat a matter of math definition and meeting tests for randomness in a population of numbers. I am not "wrong". However, for all practical purposes any method will do. Almost all generated "random" numbers are pseudorandom anyway. I admit that there are hardware solutions using electronic noise but even they will produce repeats. It's analogous to the fact that, say, 10 zeroes will occur sequentially in the digits of PI. -- James Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not |
#6
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
"James Silverton" wrote:
Joe wrote on Tue, 9 Mar 2010 09:54:20 -0800: "James Silverton" wrote: Technically, if you do not allow duplication you don't truly have random numbers. [....] Wrong! There is random selection "with replacement" and "without replacement". My aside was somewhat a matter of math definition and meeting tests for randomness in a population of numbers. I am not "wrong". LOL! Okay, more precisely, random selection "without replacement" means random selection from different populations, each population being the same as the previous ones less the previously selected things. There is nothing that is inherently "not truly random" about it. Of course, whether or not the selection is "truly random" depends on the selection process. No software pseudorandom generator (AFAIK) is "truly random". They only try to achieve the appearance of randomness. But that has nothing to do with whether or not duplication is allowed, which is all that I was commenting on. ----- original message ----- "James Silverton" wrote in message ... Joe wrote on Tue, 9 Mar 2010 09:54:20 -0800: "James Silverton" wrote: Technically, if you do not allow duplication you don't truly have random numbers. So by your definition, it is impossible to choose 6 people "at random" from a group of 49. Wrong! There is random selection "with replacement" and "without replacement". ----- original message ----- "James Silverton" wrote in message ... mike_vr wrote on Tue, 9 Mar 2010 09:19:01 -0800: Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Technically, if you do not allow duplication you don't truly have random numbers. However, there are sites that will produce both duplicated and unduplicated "random" digits, for example, http://stattrek.com/Tables/Random.aspx These could be put in a column and selected sequentially. So by your definition, it is impossible to choose 6 people "at random" from a group of 49. Wrong! There is random selection "with replacement" and "without replacement". My aside was somewhat a matter of math definition and meeting tests for randomness in a population of numbers. I am not "wrong". However, for all practical purposes any method will do. Almost all generated "random" numbers are pseudorandom anyway. I admit that there are hardware solutions using electronic noise but even they will produce repeats. It's analogous to the fact that, say, 10 zeroes will occur sequentially in the digits of PI. -- James Silverton Potomac, Maryland Email, with obvious alterations: not.jim.silverton.at.verizon.not |
#7
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
"mike_vr" wrote:
Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? Alternative.... Put =RAND() into A1:A49, copy-and-paste-special-value into B1:B49, then put the following into C1 and copy into C2:C6: =rank(B1,$B$1:$B$49) To generate a new set, copy-and-paste-special-value A1:A49 into B1:B49 again. The copy-and-paste-special-value is needed to work around the fact that RAND is a volatile function, so it changes every time any cell in the Excel file is edited. ----- original message ----- "mike_vr" wrote in message ... Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#8
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
One way...
This requires that there be a cell before the first random number cell and that cell must not contain one of the random numbers. So, let's assume you want the 6 random non-repeating numbers from 1 to 49 in the range B2:G2. Cell A2 must not contain a number from 1 to 49. Enter this array formula** in B2 and copy across to G2: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:49")),$A2:A2, 0)),ROW(INDIRECT("1:49"))),INT(RAND()*(49-(COLUMNS($A2:B2)-1)))+1) ** array formulas need to be entered using the key combination of CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT key then hit ENTER. -- Biff Microsoft Excel MVP "mike_vr" wrote in message ... Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#9
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
Correction...
For random non-repeating numbers from 1 to 49: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2, 0)),ROW(INDIRECT("1:50"))),INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1) Still array entered. -- Biff Microsoft Excel MVP "T. Valko" wrote in message ... One way... This requires that there be a cell before the first random number cell and that cell must not contain one of the random numbers. So, let's assume you want the 6 random non-repeating numbers from 1 to 49 in the range B2:G2. Cell A2 must not contain a number from 1 to 49. Enter this array formula** in B2 and copy across to G2: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:49")),$A2:A2, 0)),ROW(INDIRECT("1:49"))),INT(RAND()*(49-(COLUMNS($A2:B2)-1)))+1) ** array formulas need to be entered using the key combination of CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT key then hit ENTER. -- Biff Microsoft Excel MVP "mike_vr" wrote in message ... Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#10
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
"T. Valko" wrote:
=SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2, 0)), ROW(INDIRECT("1:50"))),INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1) Caveat emptor: that formula can return 50 in the first cell (B2). That can happen when RAND() returns 0.999999999999999 or larger (up to 0.999999999999999 + 8*2^-53, the largest value less than 1). This is due to a defect (IMHO) in INT whereby INT(49*0.999999999999999) returns 49(!). This is because that product is represented internally by exactly 48.9999999999999,502620084967929869890213012695312 5, and it appears that INT first rounds the internal representation to 15 significant digits before truncating. If you want a "correct" implementation of INT, use the following UDF instead: Function myINT(x As Double) As Double myINT = Int(x) End Function ----- original message ----- "T. Valko" wrote in message ... Correction... For random non-repeating numbers from 1 to 49: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2, 0)),ROW(INDIRECT("1:50"))),INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1) Still array entered. -- Biff Microsoft Excel MVP "T. Valko" wrote in message ... One way... This requires that there be a cell before the first random number cell and that cell must not contain one of the random numbers. So, let's assume you want the 6 random non-repeating numbers from 1 to 49 in the range B2:G2. Cell A2 must not contain a number from 1 to 49. Enter this array formula** in B2 and copy across to G2: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:49")),$A2:A2, 0)),ROW(INDIRECT("1:49"))),INT(RAND()*(49-(COLUMNS($A2:B2)-1)))+1) ** array formulas need to be entered using the key combination of CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT key then hit ENTER. -- Biff Microsoft Excel MVP "mike_vr" wrote in message ... Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#11
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
"T. Valko" wrote:
=SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2, 0)), ROW(INDIRECT("1:50"))),INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1) Some improvements: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:49")),$A2:A2, 0)), ROW(INDIRECT("1:49"))),RANDBETWEEN(1,50-COLUMNS($B2:B2))) I tested this by generating all 49 numbers in random order in B2:AX2. The use of RANDBETWEEN should avoid the anomaly with INT(49*0.999999999999999), which would cause 50 to appear in the initial cell (B2). The use of "1:49" instead of "1:50" should make no functional difference, but it seems more consistent with expectations, insofar as we expect no more than 49 selections. Moreover, I believe that the use of "1:50" exacerbates the undesired result of the anomaly with INT(x*0.999999999999999), allowing 50 to be appear in more than just the initial cell. MATCH(ROW(INDIRECT("1:50")),$A2:A2,0) should always fail for ROW(50). So ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2,0)) should always be TRUE. Thus, IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2,0)),ROW (INDIRECT("1:50")) should always result in an array that contains 50 at the end. And the size of the array is 50 initially, then 49, then 48, etc. But the intention is for INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1 to return 49 initially, then 48, then 47, etc. Thus, the intention is to have the expression SMALL(...,49) initially, then SMALL(...,48), then SMALL(...,47), etc. Ergo, with "1:50", the size of the array is always one more than it needs to. But that seems to serve no useful purpose. Even though the INT expression sometimes initially returns 50 anomalously, we would not want SMALL(...,50), since that would result in 50, which is not between 1 and 49. Moreover, using "1:50" might result in the SMALL expression returning 50 at other times, not just initially. This is because INT(48*0.999999999999999) is 49, which would select 50 in the second cell. Similarly for INT(47*0.999999999999999) etc in subsequent cells[*]. -----[*] INT(x*0.999999999999999) does work as intended for some values of x less than 11. But INT(x*(0.999999999999999+y*2^-53)) returns increasingly more unintended results as y increases, and INT(x*(0.999999999999999+8*2^-53) returns unintended results for all x less than 11. ----- original message ----- "T. Valko" wrote in message ... Correction... For random non-repeating numbers from 1 to 49: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:50")),$A2:A2, 0)),ROW(INDIRECT("1:50"))),INT(RAND()*(50-(COLUMNS($A2:B2)-1)))+1) Still array entered. -- Biff Microsoft Excel MVP "T. Valko" wrote in message ... One way... This requires that there be a cell before the first random number cell and that cell must not contain one of the random numbers. So, let's assume you want the 6 random non-repeating numbers from 1 to 49 in the range B2:G2. Cell A2 must not contain a number from 1 to 49. Enter this array formula** in B2 and copy across to G2: =SMALL(IF(ISNA(MATCH(ROW(INDIRECT("1:49")),$A2:A2, 0)),ROW(INDIRECT("1:49"))),INT(RAND()*(49-(COLUMNS($A2:B2)-1)))+1) ** array formulas need to be entered using the key combination of CTRL,SHIFT,ENTER (not just ENTER). Hold down both the CTRL key and the SHIFT key then hit ENTER. -- Biff Microsoft Excel MVP "mike_vr" wrote in message ... Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#12
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
You may consider to download and install the very assistance add-in: MOREFUNC
http://download.cnet.com/Morefunc/30...-10423159.html Now, you should select 6 cells and while selected to put the cursor into the formula bar and type: {=MRAND(,1,49)} *** This is an array formula, and is to be confirmed with CTRL+SHIFT+ENTER rather than with simply ENTER. The curly brackets {} are not to be typed manually, those are entered by the Excel, when the formula is entered as an Array formula. Micky "mike_vr" wrote: Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
#13
![]()
Posted to microsoft.public.excel.misc
|
|||
|
|||
![]()
and another but this time using vb
Sub Sonic() Dim FillRange As Range, c As Range Set FillRange = Range("A1:A6") For Each c In FillRange Do c.Value = Int((49 * Rnd) + 1) Loop Until WorksheetFunction.CountIf(FillRange, c.Value) < 2 Next End Sub -- Mike When competing hypotheses are otherwise equal, adopt the hypothesis that introduces the fewest assumptions while still sufficiently answering the question. "mike_vr" wrote: Hi there Does anyone know how I can have six cells next to each other, using the =RANDBETWEEN(1,49) function, where none of the cells equal each other? I.e. a random lottery function without having two of the same numbers. I'm trying to do this without creating a huge nested If statement so any help would be appreciated. Cheers Mike |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
RANDBETWEEN function returns #NAME? | Excel Discussion (Misc queries) | |||
How do you avoid duplicates when using the randbetween function? | Excel Worksheet Functions | |||
randbetween function | Excel Discussion (Misc queries) | |||
Why doesn't my =RANDBETWEEN function work? | Excel Discussion (Misc queries) | |||
why doesnt my RANDBETWEEN function work? | Excel Worksheet Functions |