[R] Why the slope and intercept of 95% CI varies at each calculation when using package mcr?

[Rui Barradas]

Hello,

I know nothing about package mcr but by reading the help page for 
function mcreg I conclude that CI's are calculated using a bootstrap 
resampling technique and therefore you should expect different values 
every time the function runs unless you set the random generator seed 
using ?set.seed.

Hope this helps,

Rui Barradas

Em 26-02-2017 07:51, vod vos escreveu:
>
> Hi Everybody,
>
> aa<- c(1,5,10,20,50,40,50,60,70,80,90,100,150,200,250,300,350,400,450,500,550,600,650,700,750,800,850,900,950,1000)
> bb<- c(8,16,30,24,39,54,40,68,72,62,122,80,181,259,275,380,320,434,479,587,626,648,738,766,793,851,871,957,1001,960)
>
> library(mcr)
>
> pbreg<- mcreg(aa,bb, method.reg = "PaBa")
>
> pbreg at para
>
>                 EST SE       LCI       UCI
> Intercept 7.081869 NA -2.824761 20.169193
> Slope     1.055312 NA  1.024968  1.096982
>
> but when you calculate again,
>
> pbreg<- mcreg(aa,bb, method.reg = "PaBa")
>
> pbreg at para
>
>                 EST SE       LCI       UCI
> Intercept 7.081869 NA -1.834744 20.598912
> Slope     1.055312 NA  1.025339  1.095888
>
> pbreg at para show different values of LCI and UCI compared to the first time,  how does this happen?
>
> Thanks.
>
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