Re: [R] Uniroot error message with in intergration

Many thanks Ellison I have modified it as you suggested but I have this error message <<>> I am not sure which arguments I have missed? *y <- function(t,n){ diff <- 0.5 df1 <- 2*n-2 ncp1 <- sqrt((diff^2*n)/2) p <- 1- pt(t,df=df1) test <- qt((1-p),df=df1,ncp=ncp1)*(1/sqrt(2)) return(test) }

Re: [R] Uniroot error message with in intergration

I have defined t at the beginning of my query. I have added n on uniroot below and still getting the same error message uniroot(integ,lower=0,upper=1000,n) -- View this message in context: http://r.789695.n4.nabble.com/Uniroot-error-message-with-in-intergration-tp4634247p4634264.html Sent

[R] Uniroot error message with in intergration

Dear all I am trying to calculate the value of n using uniroot. Here is the message I am having: <<< Error in uniroot(integ, lower = 0, upper = 1000, n) : 'interval' must be a vector of length 2 >>> Please would you be able to give me an indication on why I am having this error message.

[R] How to compute boundaries for bivariate normal distribution in group sequential design

Hi all Dear all, I need to compute boundaries for 3 stages group sequential design with 2 variables using Simpson’s integration method. There is a r program written by Michael A. Proschant et Al. (2006) (Statistical Monitoring of Clinical Trials: A Unified Approach) – see file attached – to calc

[R] Uniroot error

Dear All I am trying to find a uniroot of a function within another function (see example) but I am getting an error message (f()values at end points not of opposite sign). I was wondering if you would be able to advise how redefine my function so that I can find the solution. In short my first fu