CODEWITHSUNDEEP
rglm
Rob Sedgwick
Rob Sedgwick

Reputation: 4514

glm probit "cannot find valid starting values" error message

I am trying to use R for the first time to do some probit analaysis.

I get the following error:

Error in if (!(validmu(mu) && valideta(eta))) stop("cannot find valid starting values: please specify some", : missing value where TRUE/FALSE needed

This is the command I am using:

 m1=glm(Good~Stg.Days+Dev.Deployments+Check.Ins+NoOfDevelopers,family=poisson(link = "probit"),data=deploy[1:4,])

My data deploy[1:4,] are as loaded in from a CSV file follows:

Good,Application Type,Project,Start Date,End Date,Stg Days,Dev Deployments,Check Ins,NoOfDevelopers
1,DocumentPlatform,ZCP,11/08/2010,11/11/2010,0.6,0,12,4
1,DocumentPlatform,ZCP,11/11/2010,09/12/2010,0.4,0,4,1
0,DocumentPlatform,ZCP,09/12/2010,07/03/2011,10,0,7,3
1,FactsheetPlatform,Process.ARCH,28/06/2010,09/03/2011,7.1,0,18,2

deploy is in reality a much bigger vector than 1:4 I am just using a subset of the data to help determine the problem.

Any ideas what is wrong?

Upvotes: 0

Views: 2216

Answers (1)

Freddy
Freddy

Reputation: 419

As i commented: Using ?glm I found tha the poisoon family supports the following links: log, identity, and sqrt.

Testing on another link:

test <- data.frame('Good'=c(1,1,0,1),'Stg Days'=c(0.6,0.4,10,7.1),'Dev Deployments'=c(0,0,0,0),'Check Ins'=c(12,4,7,18),'NoOfDevelopers'=c(4,1,3,2))
m1=glm(Good~ . ,family=poisson(link = "log"),data=test)

Gives no errors. So I think your link = "probit" is the problem.

Upvotes: 1

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