[R] Is there in R a function equivalent to the mround, as found in most spreadsheets?

[Duncan Murdoch]

On 5/6/2008 12:07 PM, Dr. Ottorino-Luca Pantani wrote:
> Dear R-users,
> I have the following problem
> 
> In a lab experiment I have to mix three solutions to get different 
> concentrations of various molecules in a cuvette
> 
> I've used R to calculate the necessary µliters for each of the level of 
> the experiment and I must confess that it is more useful and easier to 
> achieve the results than using spreadsheets.
> 
> But there's a problem.
> 
> Imagine that for a particular cuvette (I have 112 different cuvettes !!) 
> you have to mix the following volumes of solution A, B, and C respectively.
> 
> c(1803.02, 193.51, 3.47)
> 
> Each solution is to be taken with 3 different pipettes (5000, 250 and 10 
> µL Volume max) and each of those delivers volumes in steps of 50 µL,  5 
> µL  or 1µL, respectively
> Since the above values  would eventually become
> 
> c(1800, 195, 3)
> 
> it is then necessary to recalculate all the final concentrations
> of A, B and C, because the volumes are changed.
> 
> 
> I know that in most spreadsheets (Calc in Open Office, Gnumeric, Excel 
> and so on)
> there's a function such as
> 
> mround(num; num)
> 
> that give the results I need, but I want to learn more on R functions.
> 
> 
> I played a little with R functions such as
> 
> round, signif, ceiling, trunc, and floor
> 
> but without success.
> Any hint to solve this problem ?


I believe this function matches the description in OOO:

mround <- function(number, multiple) multiple * round(number/multiple)

Duncan Murdoch