Using RAND() with Different Distributions!?

And similarly, you can use other INV functions with RAND() generate
random numbers that follow other distributions. Unfortunately, Pre-2003
INV functions are too crude to do this well (which also means that ATP
does it poorly).

Jerry

barrfly wrote:

> unfortunately no. The rand() function only delivers a random number
> that is uniformly distributed between 0 and 1. You can use the
> norminv(rand()) function combination to create a normally distributed
> random number with a mean and stdev of your choosing.

Jerry,
It's worse yet with ATP, because it uses its own rng. It is SO bad that I
would like to know the algorithm. I think I posted some VBA code a while
back to show how lousy it is; you can use it to generate 10000 values; then
sort them and do a frequency count. You'll find some mighty strange stuff;
quite a few numbers get repeated, and some values get repeated 7 or 8 times,
depending on the seed. Suggest to the good folks at MS to eviscerate the
thing, please.

Regards,
Dave B

"Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
news:42EEE30E.2050301@no_e-mail.com...
> And similarly, you can use other INV functions with RAND() generate random
> numbers that follow other distributions. Unfortunately, Pre-2003 INV
> functions are too crude to do this well (which also means that ATP does it
> poorly).
>
> Jerry
>
> barrfly wrote:
>
>> unfortunately no. The rand() function only delivers a random number
>> that is uniformly distributed between 0 and 1. You can use the
>> norminv(rand()) function combination to create a normally distributed
>> random number with a mean and stdev of your choosing.
>

Hey, David! Good to see you again! How are you?

--
Kind regards,

Niek Otten

Microsoft MVP - Excel

"David J. Braden" <dbraden@nomail.invalid> wrote in message
news:uu9UKP5lFHA.2484@TK2MSFTNGP15.phx.gbl...
> Jerry,
> It's worse yet with ATP, because it uses its own rng. It is SO bad that I
> would like to know the algorithm. I think I posted some VBA code a while
> back to show how lousy it is; you can use it to generate 10000 values;
> then sort them and do a frequency count. You'll find some mighty strange
> stuff; quite a few numbers get repeated, and some values get repeated 7 or
> 8 times, depending on the seed. Suggest to the good folks at MS to
> eviscerate the thing, please.
>
> Regards,
> Dave B
>
> "Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
> news:42EEE30E.2050301@no_e-mail.com...
>> And similarly, you can use other INV functions with RAND() generate
>> random numbers that follow other distributions. Unfortunately, Pre-2003
>> INV functions are too crude to do this well (which also means that ATP
>> does it poorly).
>>
>> Jerry
>>
>> barrfly wrote:
>>
>>> unfortunately no. The rand() function only delivers a random number
>>> that is uniformly distributed between 0 and 1. You can use the
>>> norminv(rand()) function combination to create a normally distributed
>>> random number with a mean and stdev of your choosing.
>>
>
>

And I repeat Niek's "Hey."

C^2
Conrad Carlberg

And similarly, you can use other INV functions with RAND() generate
random numbers that follow other distributions. Unfortunately, Pre-2003
INV functions are too crude to do this well (which also means that ATP
does it poorly).

Jerry

barrfly wrote:

> unfortunately no. The rand() function only delivers a random number
> that is uniformly distributed between 0 and 1. You can use the
> norminv(rand()) function combination to create a normally distributed
> random number with a mean and stdev of your choosing.

Jerry,
It's worse yet with ATP, because it uses its own rng. It is SO bad that I
would like to know the algorithm. I think I posted some VBA code a while
back to show how lousy it is; you can use it to generate 10000 values; then
sort them and do a frequency count. You'll find some mighty strange stuff;
quite a few numbers get repeated, and some values get repeated 7 or 8 times,
depending on the seed. Suggest to the good folks at MS to eviscerate the
thing, please.

Regards,
Dave B

"Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
news:42EEE30E.2050301@no_e-mail.com...
> And similarly, you can use other INV functions with RAND() generate random
> numbers that follow other distributions. Unfortunately, Pre-2003 INV
> functions are too crude to do this well (which also means that ATP does it
> poorly).
>
> Jerry
>
> barrfly wrote:
>
>> unfortunately no. The rand() function only delivers a random number
>> that is uniformly distributed between 0 and 1. You can use the
>> norminv(rand()) function combination to create a normally distributed
>> random number with a mean and stdev of your choosing.
>

Hey, David! Good to see you again! How are you?

--
Kind regards,

Niek Otten

Microsoft MVP - Excel

"David J. Braden" <dbraden@nomail.invalid> wrote in message
news:uu9UKP5lFHA.2484@TK2MSFTNGP15.phx.gbl...
> Jerry,
> It's worse yet with ATP, because it uses its own rng. It is SO bad that I
> would like to know the algorithm. I think I posted some VBA code a while
> back to show how lousy it is; you can use it to generate 10000 values;
> then sort them and do a frequency count. You'll find some mighty strange
> stuff; quite a few numbers get repeated, and some values get repeated 7 or
> 8 times, depending on the seed. Suggest to the good folks at MS to
> eviscerate the thing, please.
>
> Regards,
> Dave B
>
> "Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
> news:42EEE30E.2050301@no_e-mail.com...
>> And similarly, you can use other INV functions with RAND() generate
>> random numbers that follow other distributions. Unfortunately, Pre-2003
>> INV functions are too crude to do this well (which also means that ATP
>> does it poorly).
>>
>> Jerry
>>
>> barrfly wrote:
>>
>>> unfortunately no. The rand() function only delivers a random number
>>> that is uniformly distributed between 0 and 1. You can use the
>>> norminv(rand()) function combination to create a normally distributed
>>> random number with a mean and stdev of your choosing.
>>
>
>

And I repeat Niek's "Hey."

C^2
Conrad Carlberg

Hi everyone,

In Excel, by going to Tools/Data Analysis/Random Number Generation,
then clicking ok and going to "Distribution" window, you can select any
distribution available (uniform, normal, ....etc.)

Now, after I make a selection to a distribution, and then using RAND(),
wont that mean that my random numbers do follow the selected
distribution?

Thanks,
Mike

No. the random number generation in data analysis willl generate a table of
random numbers with the given distribution, but it does not change the
Rand() factorr

"mas_it_2000@yahoo.com" wrote:

> Hi everyone,
>
> In Excel, by going to Tools/Data Analysis/Random Number Generation,
> then clicking ok and going to "Distribution" window, you can select any
> distribution available (uniform, normal, ....etc.)
>
> Now, after I make a selection to a distribution, and then using RAND(),
> wont that mean that my random numbers do follow the selected
> distribution?
>
> Thanks,
> Mike
>
>

And similarly, you can use other INV functions with RAND() generate
random numbers that follow other distributions. Unfortunately, Pre-2003
INV functions are too crude to do this well (which also means that ATP
does it poorly).

Jerry

barrfly wrote:

> unfortunately no. The rand() function only delivers a random number
> that is uniformly distributed between 0 and 1. You can use the
> norminv(rand()) function combination to create a normally distributed
> random number with a mean and stdev of your choosing.

Jerry,
It's worse yet with ATP, because it uses its own rng. It is SO bad that I
would like to know the algorithm. I think I posted some VBA code a while
back to show how lousy it is; you can use it to generate 10000 values; then
sort them and do a frequency count. You'll find some mighty strange stuff;
quite a few numbers get repeated, and some values get repeated 7 or 8 times,
depending on the seed. Suggest to the good folks at MS to eviscerate the
thing, please.

Regards,
Dave B

"Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
news:42EEE30E.2050301@no_e-mail.com...
> And similarly, you can use other INV functions with RAND() generate random
> numbers that follow other distributions. Unfortunately, Pre-2003 INV
> functions are too crude to do this well (which also means that ATP does it
> poorly).
>
> Jerry
>
> barrfly wrote:
>
>> unfortunately no. The rand() function only delivers a random number
>> that is uniformly distributed between 0 and 1. You can use the
>> norminv(rand()) function combination to create a normally distributed
>> random number with a mean and stdev of your choosing.
>

Hey, David! Good to see you again! How are you?

--
Kind regards,

Niek Otten

Microsoft MVP - Excel

"David J. Braden" <dbraden@nomail.invalid> wrote in message
news:uu9UKP5lFHA.2484@TK2MSFTNGP15.phx.gbl...
> Jerry,
> It's worse yet with ATP, because it uses its own rng. It is SO bad that I
> would like to know the algorithm. I think I posted some VBA code a while
> back to show how lousy it is; you can use it to generate 10000 values;
> then sort them and do a frequency count. You'll find some mighty strange
> stuff; quite a few numbers get repeated, and some values get repeated 7 or
> 8 times, depending on the seed. Suggest to the good folks at MS to
> eviscerate the thing, please.
>
> Regards,
> Dave B
>
> "Jerry W. Lewis" <post_a_reply@no_e-mail.com> wrote in message
> news:42EEE30E.2050301@no_e-mail.com...
>> And similarly, you can use other INV functions with RAND() generate
>> random numbers that follow other distributions. Unfortunately, Pre-2003
>> INV functions are too crude to do this well (which also means that ATP
>> does it poorly).
>>
>> Jerry
>>
>> barrfly wrote:
>>
>>> unfortunately no. The rand() function only delivers a random number
>>> that is uniformly distributed between 0 and 1. You can use the
>>> norminv(rand()) function combination to create a normally distributed
>>> random number with a mean and stdev of your choosing.
>>
>
>

And I repeat Niek's "Hey."

C^2
Conrad Carlberg