[BioC] build a chromLocation object for SNP locations, not genes

[Paul Shannon]

I wish to build a chromLocation object and display it with geneplotter.

However, I am not interested in gene locations.  Instead, I want to  
examine the density and distribution of SNPs across a chromosome.  So  
I begin with simple chromosomal locations for many SNPs.

I found some documentation; 'How to Assemble a chromLocation Object'  
seemed especially promising.  But it turns out that this is  
specialized on buiding a chromLocation object from a data package (in  
this case, hu6800.db).

Can I get some guidance on building a chromLocation object from  
scratch, starting with just a set of SNP coordinates?

Thanks,

  - Paul