I have fitted a logistic regression model> failed.lr2$calllrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, na.action = na.omit) using the Design package functions and would like to generate a nomogram from this model. the datadist information is generated and stored in> ddisttime.long$Age time.long$task2 Low:effect 45 <NA> Adjust to 56 both.foam High:effect 68 <NA> Low:prediction 21 both.foam High:prediction 80 right Low 20 both.foam High 80 right Values: time.long$task2 : both.foam left right>The model fitted and then when I try the nomgram function> nomogram(failed.lr2)Error in value.chk(at, i, NA, -nint, Limval, type.range = "full") : variable Age does not have limits defined by datadist>I get an error. The NA values in ddist seem to be the problem but I don't understand the datadist information. Can anyone help explain why this is failing. Thanks Ross Darnell -- University of Queensland, Brisbane QLD 4067 AUSTRALIA Email: <r.darnell at uq.edu.au> Phone +61 7 3365 6087 http://www.shrs.uq.edu/shrs/school_staff/ross_darnell.html
On Wed, 05 Nov 2003 09:22:34 +1000 Ross Darnell <r.darnell at uq.edu.au> wrote:> I have fitted a logistic regression model > > > failed.lr2$call > lrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, > na.action = na.omit)Use Age*task2 and omit na.action as na.omit is the default> > using the Design package functions and would like to generate a > nomogram from this model. > > the datadist information is generated and stored in > > > ddist > time.long$Age time.long$task2 > Low:effect 45 <NA> > Adjust to 56 both.foam > High:effect 68 <NA> > Low:prediction 21 both.foam > High:prediction 80 right > Low 20 both.foam > High 80 rightThis looks most strange. You did not include the original code but I suspect you had $ in a term. $ should not appear in column headings above. Design wants you to use data= or attach, and avoid $ in terms. Frank Harrell> > Values: > > time.long$task2 : both.foam left right > > > > The model fitted and then when I try the nomgram function > > > nomogram(failed.lr2) > Error in value.chk(at, i, NA, -nint, Limval, type.range = "full") : > variable Age does not have limits defined by datadist > > > > I get an error. The NA values in ddist seem to be the problem but I > don't understand the datadist information. > > Can anyone help explain why this is failing. > > Thanks > > Ross Darnell > > -- > > University of Queensland, Brisbane QLD 4067 AUSTRALIA > Email: <r.darnell at uq.edu.au> > Phone +61 7 3365 6087 > http://www.shrs.uq.edu/shrs/school_staff/ross_darnell.html--- Frank E Harrell Jr Professor and Chair School of Medicine Department of Biostatistics Vanderbilt University
Frank Harrell wrote> On Wed, 05 Nov 2003 09:22:34 +1000 > Ross Darnell <r.darnell at uq.edu.au> wrote: > > > I have fitted a logistic regression model > > > > > failed.lr2$call > > lrm(formula = failed ~ Age + task2 + Age:task2, data = time.long, > > na.action = na.omit) > > Use Age*task2 and omit na.action as na.omit is the default > > > > > using the Design package functions and would like to generate a > > nomogram from this model. > > > > the datadist information is generated and stored in > > > > > ddist > > time.long$Age time.long$task2 > > Low:effect 45 <NA> > > Adjust to 56 both.foam > > High:effect 68 <NA> > > Low:prediction 21 both.foam > > High:prediction 80 right > > Low 20 both.foam > > High 80 right > > This looks most strange. You did not include the original code but I > suspect you had $ in a term. $ should not appear in column headings > above. Design wants you to use data= or attach, and avoid $ in terms. > > > > > > Values: > > > > time.long$task2 : both.foam left right > > > > > > > The model fitted and then when I try the nomgram function > > > > > nomogram(failed.lr2) > > Error in value.chk(at, i, NA, -nint, Limval, type.range = "full") : > > variable Age does not have limits defined by datadist > > > > > > > I get an error. The NA values in ddist seem to be the problem but I > > don't understand the datadist information. > >I tried using the data argument in datadist> names(my.data)[1] "subject" "Age" "failed" "task"> ddist <- datadist(Age,task,data=my.data)Error in datadist(Age, task, data = my.data) : Object "Age" not found Strange. Thanks Ross Darnell --