[R] [FORGED] Generating random data with non-linear correlation between two variables

[Muhammad Bilal]

The goal is to test a developed model against two sets of hypothetical data, where the relationship between on data set is linear whereas non-linear (e.g., polynomial) with another. However, the distributions of the v1 and v2 should not be other than normal or slightly positively skewed or slightly negatively skewed. 

In Oracle, random data is generated with packaged function dbms_random.value(lowerbound, upperbound), which can be called from SQL query with where clause (level <= no_of_rows) for the number of rows you want.

After the rows are generated, we can write custom functions to spread the data points along the y-axis, so that they wouldn't overlap. 

I hope this may clear the use case further.

Many Thanks and 

Kind Regards
--
Muhammad Bilal


Research Assistant and Doctoral Researcher,
Bristol Enterprise, Research, and Innovation Centre (BERIC),
University of the West of England (UWE),
Frenchay Campus,
Bristol,
BS16 1QY 


muhammad2.bilal at live.uwe.ac.uk

    
________________________________________
From: David R Forrest <drf at vims.edu>
Sent: 09 April 2016 11:48
To: Muhammad Bilal
Cc: Rolf Turner; r-help at r-project.org
Subject: Re: [R] [FORGED] Generating random data with non-linear correlation between two variables

Please specify your goal in the oracle/psql analytical functions you know or specify what you mean by nonlinear correlation

Sent from my iPhone

> On Apr 9, 2016, at 6:09 AM, Muhammad Bilal <Muhammad2.Bilal at live.uwe.ac.uk> wrote:
>
> No its not. I am doing all these experiments for my own learning purpose. I am Oracle SQL & PLSQL programmer and  I can do these things with Oracle analytical functions.
>
> However at present I am keen to learn R, with no other interest right now.
>
> Thanks
> --
> Muhammad Bilal
> Research Assistant and PhD Student,
> Bristol Enterprise, Research and Innovation Centre (BERIC),
> University of the West of England (UWE),
> Frenchay Campus,
> Bristol,
> BS16 1QY
>
> muhammad2.bilal at live.uwe.ac.uk
>
>
> ________________________________________
> From: Rolf Turner <r.turner at auckland.ac.nz>
> Sent: 09 April 2016 04:46
> To: Muhammad Bilal
> Cc: r-help at r-project.org
> Subject: Re: [FORGED] [R] Generating random data with non-linear correlation between two variables
>
>> On 09/04/16 06:57, Muhammad Bilal wrote:
>> Hi All,
>>
>> I am new to R and don't know how to achieve it.
>>
>> I am interested in generating a hypothetical dataframe that is consisted of say two variables named v1 and v2, based on the following constraints:
>> 1. The range of v1 is 500-1500.
>> 2. The mean of v1 is say 1100
>> 3. The range of v2 is 300-950.
>> 4. The mean of v2 is say 400
>> 5. There exists a positive trend between these two variables, meaning that as v1 increases, v2 be also increase.
>> 6. But the trend should be slightly non-linear. i.e., curved line.
>>
>> Is it possible to automatically generate through functions like rnorm.
>>
>> Any help will be highly appreciated.
>
> This sounds to me very much like a homework problem.  We don't do
> people's homework for them on this list.
>
> cheers,
>
> Rolf Turner
>
> --
> Technical Editor ANZJS
> Department of Statistics
> University of Auckland
> Phone: +64-9-373-7599 ext. 88276
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