[R] Mclust problem with mclust1Dplot: Error in to - from : non-numeric argument to binary operator

[Emmanuel Levy]

Dear All,

I haven't found a solution to the "variance" problem. However, I could
solve the plotting problem by plotting the data myself.
I think that the problem is due to a change in the data structure
returned by the function Mclust.

The web-page:
http://www.childrensmercy.org/stats/weblog2006/UnivariateClustering.asp
has been extremely helpful.

I paste the code below for people's future reference.

par(mfcol=c(1,2),mar=c(2.1,0.1,0.1,0.1))
v <- Mclust(my.data)
x0 <- seq(min(my.data),max(my.data),length.out=100)
nt <- rep(0,100)
plot(range(my.data),c(0,0.15),type="n",xlab=" ",ylab=" ",axes=F, ylim=c(0,0.4) )
axis(side=1)
for (i in 1:2) {
  ni <- v$parameters$pro[i]*dnorm(x0,
mean=as.numeric(v$parameters$mean[i]),sd=1)
  lines(x0,ni,col=1)
  nt <- nt+ni
 }
lines(x0,nt,lwd=3)
segments(my.data,0,my.data,0.02)

Best,

Emmanuel



2008/10/21 Emmanuel Levy <emmanuel.levy at gmail.com>:
> After playing with the data, I figured out what the problem is:
> I've got many zeros in the dataset, which probably induces the
> algorithm to determine a gaussian with variance=0.
>
> If I remove the zeros it works, but then the decomposition is not as
> it should be ....
>
> Any idea on how to solve this would be great; is it possible to
> somehow force the parameters (e.g variance) to be
> greater than a particular threshold?
>
> Thanks,
>
> Emmanuel
>
>
>
> 2008/10/20 Emmanuel Levy <emmanuel.levy at gmail.com>:
>> Dear list members,
>>
>> I am using Mclust in order to deconvolute a distribution that I
>> believe is a sum of two gaussians.
>>
>> First I can make a model:
>>> my.data.model = Mclust(my.data, modelNames=c("E"), warn=T, G=1:3)
>>
>> But then, when I try to plot the result, I get the following error:
>>
>>> mclust1Dplot(my.data.model, parameters = my.data.model$parameters, what = "density")
>> Error in to - from : non-numeric argument to binary operator
>>
>> Also, I'd like to allow for each gaussian to have a different variance
>> (modelNmaes=c("V")) , but then I get another error message:
>>
>>> my.data.model = Mclust(my.data, modelNames=c("V"), warn=T, G=1:3)
>> Warning messages:
>> 1: In meV(data = data, z = z, prior = prior, control = control, warn = warn) :
>>  sigma-squared falls below threshold
>> 2: In meV(data = data, z = z, prior = prior, control = control, warn = warn) :
>>  sigma-squared falls below threshold
>> 3: In summary.mclustBIC(Bic, data, G = G, modelNames = modelNames) :
>>  best model occurs at the min or max # of components considered
>> 4: In Mclust(my.data, modelNames = c("V"), warn = T, G = 1:3) :
>>  optimal number of clusters occurs at min choice
>>
>> Many thanks in advance for your help,
>>
>> Best wishes,
>>
>> Emmanuel
>>
>>
>> If you would like to reproduce the above, the dataset is:
>>
>> my.data=c( 0.0000,0.0052,0.0000,-0.2136,0.4625,0.6047,0.0000,0.7370,0.5059
>> ,-0.8060,-1.0790,0.0000,-1.5397,-0.0720,-3.2180,-1.6980,0.0000,2.2845
>> ,-1.0741,0.0000,0.1020,-0.6010,0.2210,-0.0120,1.0785,0.0000,-0.4536
>> ,-0.1127,-0.2032,-0.0421,-1.6818,-0.9935,-2.2105,-0.7963,-0.1820,-2.0468
>> ,0.6161,-1.7663,-0.6800,-2.1290,-0.0167,0.0000,0.0000,0.0000,0.5427
>> ,-0.0170,0.0000,0.0000,-0.6576,0.9055,0.1409,-0.1409,0.0000,0.3730
>> ,-0.1800,-1.3141,0.6786,-0.2480,-2.5110,-0.1340,0.3000,-1.7350,0.0000
>> ,-0.5464,0.0000,-0.7513,-1.9056,-1.4823,-0.5376,-0.4516,-1.1391,0.0000
>> ,-2.2560,1.3770,0.3390,-2.6023,-1.0880,-0.1444,0.0000,-0.1459,0.1740
>> ,0.0000,0.3310,0.0749,1.0360,-0.8345,-0.6843,-3.5171,-1.9482,-0.4972
>> ,-0.0130,-2.0290,-0.2812,0.0000,0.0000,-0.0164,0.0000,-1.9220,-1.5941
>> ,-1.0840,0.0000,0.0459,-2.2121,-1.1485,-1.1485,0.0000,-0.4449,-0.5001
>> ,0.3520,1.9980,-3.8385,1.7160,1.0020,-0.2250,-0.8265,-0.2032)
>>
>