Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

From |
Yu Xue <snowrain@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Questions for random data generation and value label |

Date |
Mon, 11 Mar 2013 15:28:48 -0500 |

Thanks Maarten, David, Nick, Joerg ! Let me use an example to describe my question more clearly. There is an actual data that has three variables: Var1, Var2, Var3. Each of them has continuous numeric values. And I get the max, min, SD, mean for each of them, and save them in several macros, and then clear the memory. Then, I want to generate a synthetic data, which also include three variables: SynVar1, SynVar2, SynVar3. And they keep the same max, min, SD, mean of Var1, Var2, Var3, respectively as in actual data. Hope I describe it clearly. Thank you very much On Mon, Mar 11, 2013 at 12:48 PM, Joerg Luedicke <joerg.luedicke@gmail.com> wrote: > The normal distribution has support -infinity,+infinity, so it is not > clear what you mean with 'range' here. Do you want to draw from a > truncated normal distribution? > > Joerg > > On Mon, Mar 11, 2013 at 12:49 PM, Yu Xue <snowrain@gmail.com> wrote: >> Thanks Maarten! >> >> What I want is Normal Distribution. Is there a way to randomly >> generate a variable with specific mean, SD, and range, >> >> Thanks!! >> Mark >> >> On Mon, Mar 11, 2013 at 10:35 AM, Maarten Buis <maartenlbuis@gmail.com> wrote: >>> On Mon, Mar 11, 2013 at 4:20 PM, Yu Xue wrote: >>>> I already checked "-help random_number_functions-", but I still can >>>> not find the answer to my question. >>>> >>>> I knew that I can use a formula similar like this: >>>> Var=a+int((b-a+1)*runiform()), to keep a specific range in [a,b] >>>> and use another formula: Var=invnorm(uniform())*SD+mean, to keep >>>> specific Standard deviation and mean. >>>> But I do not know how to generate a "Var" with all specific range, SD, and mean. >>>> Please note that I do not generate a sample data from the actual data, >>>> what I want to generate is synthetic data (totally fake data). >>> >>> What distribution do you want to draw your new variable from? Do you >>> want it to be normally (Gaussian) distributed, gamma distributed, beta >>> distribed, Fisk distributed, Laplace distributed, ... The number of >>> choices is huge, but without choosing your distribution you cannot >>> draw your random numbers. >>> >>> -- Maarten >>> >>> >>> --------------------------------- >>> Maarten L. Buis >>> WZB >>> Reichpietschufer 50 >>> 10785 Berlin >>> Germany >>> >>> http://www.maartenbuis.nl >>> --------------------------------- * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: Questions for random data generation and value label***From:*"Joseph Coveney" <stajc2@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Joerg Luedicke <joerg.luedicke@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Nick Cox <njcoxstata@gmail.com>

**References**:**st: Questions for random data generation and value label***From:*Yu Xue <snowrain@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Yu Xue <snowrain@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Maarten Buis <maartenlbuis@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Yu Xue <snowrain@gmail.com>

**Re: st: Questions for random data generation and value label***From:*Joerg Luedicke <joerg.luedicke@gmail.com>

- Prev by Date:
**Re: st: Problem with decile significance test** - Next by Date:
**st: question on ivreg2, ivendog and "good" instruments** - Previous by thread:
**Re: st: Questions for random data generation and value label** - Next by thread:
**Re: st: Questions for random data generation and value label** - Index(es):