Re: [R] Error in chol.default

The error msg says it all if you know how to read it. > When I run the optimization (given that I can't find parameters that > fit the data by eyeball), I get the error: > ``` > Error in chol.default(object$hessian) : > the leading minor of order 1 is not positive definite Your Jacobian

[R] Error in chol.default

Hello, I am trying to fit a Richards model to some cumulative incidence data of infection. I got this example: ``` rich = function(p, x) { a = p["curvature"] k = p["finalPop"] r = p["growthRate"] y = r * x * (1-(x/k)^a) return(y) } ricky = function(p, x, y) p$r * x * (1-(x/p$k)^p$a) -y #

Re: [R] error in chol.default((value + t(value))/2) : , the leading minor of order 1 is not positive definite

> On May 5, 2018, at 1:19 AM, Troels Ring wrote: > > Dear friends - I'm having troubles with nlme fitting a simplified model as > shown below eliciting the error > > Error in chol.default((value + t(value))/2) : > the leading minor of order 1 is not positive definite - > >

[R] error in chol.default((value + t(value))/2) : , the leading minor of order 1 is not positive definite

Dear friends - I'm having troubles with nlme fitting a simplified model as shown below eliciting the error Error in chol.default((value + t(value))/2) :   the leading minor of order 1 is not positive definite - I have seen the threads on this error but it didn't help me solve the problem.