Re: [R] Variable name as string

2010-10-17 Thread Jan private
So here is the next version. Why does the intercept needs lower.tail=TRUE to give the same result as summary() for value=0? # See Verzani, simpleR (pdf), p. 80 coeff.test - function(lm.result, idx, value) { # idx = 1 is the intercept, idx1 the other coefficients # null hypothesis: coeff =

[R] Variable name as string

2010-10-16 Thread Jan private
Hello, from Verzani, simpleR (pdf), p. 80, I created the following function to test the coefficient of lm() against an arbitrary value. coeff.test - function(lm.result, var, coeffname, value) { # null hypothesis: coeff = value # alternative hypothesis: coeff != value es - resid(lm.result)

Re: [R] Variable name as string

2010-10-16 Thread Jan private
coeffname - deparse(substitute(var)) Is that what you wanted? Yes! That gets rid of the extra parameter. Thanks __ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-18 Thread Jan private
Hello Petr, thank you for your ideas. The split() looks most realistic. What about this idea: 1. Define three functions Refun1, Refun2, Refun3 for the three different sections of the calculations (same as you suggested) 2. lambda = (Re = 2320) * Refun1(Re) + ((Re 2320) (Re 65 * dk)) *

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-17 Thread Jan private
Hello Petr, but I think this is how your code really works. Did you try it? it does, but the R documentation says somewhere: Warning: for() loops are used in R code much less often than in compiled languages. Code that takes a `whole object' view is likely to be both clearer and faster in R.

Re: [R] Odp: Programming: loop versus vector oriented

2010-09-16 Thread Jan private
Hello Petr, If you want to get results of your function for a vector of reynolds and dk you can use function outer and probably get rid of for cycle in the function. outer(c(100, 530,2410), c(10, 150,200),lambda_wall) [,1] [,2] [,3] [1,] 0.640 0.6400

[R] Programming: loop versus vector oriented

2010-09-15 Thread Jan private
Dear all, I am new to R and to it's programming philosophy. The following function is supposed to work on a vector, but I can't figure out how to do that without looping through every element of it. Is there a more elegant way? Note: I have shortened it, so it is NOT correct from the pipe

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

[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,