Re: [R] Calculating with tolerances (error propagation)

2010-09-10 Thread David Winsemius
On Sep 9, 2010, at 10:57 AM, David Winsemius wrote: On Sep 9, 2010, at 6:50 AM, Jan private wrote: Hello Bernardo, - If I understood your problem this script solve your problem: q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q*h [1] 2.475 7.500 12.625 - OK, this solves the

Re: [R] Calculating with tolerances

2010-09-09 Thread Bernardo Rangel Tura
On Thu, 2010-09-09 at 09:16 +0430, Jan private wrote: Dear list, I am from an engineering background, accustomed to work with tolerances. For example, I have measured Q = 0.15 +- 0.01 m^3/s H = 10 +- 0.1 m and now I want to calculate P = 5 * Q * H and get a value with a

Re: [R] Calculating with tolerances (error propagation)

2010-09-09 Thread Jan private
Hello Bernardo, - If I understood your problem this script solve your problem: q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q*h [1] 2.475 7.500 12.625 - OK, this solves the simple example. But what if the example is not that simple. E.g. P = 5 * q/h Here, to get the maximum

Re: [R] Calculating with tolerances (error propagation)

2010-09-09 Thread David Winsemius
On Sep 9, 2010, at 6:50 AM, Jan private wrote: Hello Bernardo, - If I understood your problem this script solve your problem: q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q*h [1] 2.475 7.500 12.625 - OK, this solves the simple example. But what if the example is not that

Re: [R] Calculating with tolerances (error propagation)

2010-09-09 Thread Peng, C
q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q/h[3:1] [1] 0.02475248 0.0750 0.12626263 -- View this message in context: http://r.789695.n4.nabble.com/Re-Calculating-with-tolerances-error-propagation-tp2532640p2532991.html Sent from the R help mailing list archive at Nabble.com.

Re: [R] Calculating with tolerances (error propagation)

2010-09-09 Thread David Winsemius
On Sep 9, 2010, at 6:50 AM, Jan private wrote: Hello Bernardo, - If I understood your problem this script solve your problem: q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q*h [1] 2.475 7.500 12.625 - OK, this solves the simple example. But what if the example is not that

Re: [R] Calculating with tolerances (error propagation)

2010-09-09 Thread Keith Jewell
Jan private jrheinlaen...@gmx.de wrote in message news:1284029454.2740.361.ca...@localhost.localdomain... Hello Bernardo, - If I understood your problem this script solve your problem: q-0.15 + c(-.1,0,.1) h-10 + c(-.1,0,.1) 5*q*h [1] 2.475 7.500 12.625 - OK, this

Re: [R] Calculating with tolerances

2010-09-09 Thread Carl Witthoft
That won't do much good. Tolerances don't add (except in rare circumstances), and certainly not when they're in different units. There's nothing wrong with the first part, i.e. setting up variables whose contents include the mean and the tolerance, but is that peak? or sigma? and so on.

Re: [R] Calculating with tolerances

2010-09-09 Thread Kjetil Halvorsen
I tried RSiteSearch(Interval aritmetic) which gives zero hits. There exist a http://www.boost.org/ free software library for interval aritmetic, which it shoub be possible to link to R. Kjetil On Thu, Sep 9, 2010 at 6:28 PM, Carl Witthoft c...@witthoft.com wrote: That won't do much good.  

Re: [R] Calculating with tolerances

2010-09-09 Thread Jeff Newmiller
I think the reason this type of computation is not performed more routinely is the correlation issue. If two quantities are negatively correlated, the standard deviation of a result computed with them may actually be smaller (percentage-wise) than the larger off the original two standard

[R] Calculating with tolerances

2010-09-08 Thread Jan private
Dear list, I am from an engineering background, accustomed to work with tolerances. For example, I have measured Q = 0.15 +- 0.01 m^3/s H = 10 +- 0.1 m and now I want to calculate P = 5 * Q * H and get a value with a tolerance +- What is the elegant way of doing this in R? Thank you,