[R] matrix data appears corrupted.. appears to be pairs of decimal numbers glommed together

[David Winsemius]

On Dec 3, 2009, at 3:02 PM, Stephen Grubb wrote:

> Hello,
>
> We are occasionally getting matrix results that appear to be  
> corrupted... here are the last several rows of an example, copy- 
> pasted out of the R command window.  These are supposed to be  
> floating point numbers.
>
> [25015,]  1.820848e-01-3.2090e-06i
> [25016,]  2.178046e-01-4.8140e-06i
> [25017,]  1.820848e-01-3.2090e-06i
> [25018,]  1.820848e-01-3.2090e-06i
> [25019,]  1.144594e-01-1.6657e-06i
> [25020,]  1.820848e-01-3.2090e-06i
> [25021,] -1.293271e-01+4.3889e-06i
> [25022,]  1.144594e-01-1.6657e-06i
> [25023,]  1.820848e-01-3.2090e-06i
> [25024,]  1.820848e-01-3.2090e-06i
> [25025,]  1.173487e-01-4.4415e-07i
> [25026,]  1.820848e-01-3.2090e-06i
> [25027,]  1.375304e-01-3.6167e-06i
> [25028,]  1.820848e-01-3.2090e-06i
> [25029,] -1.293271e-01+4.3889e-06i
> [25030,]  1.820848e-01-3.2090e-06i
> [25031,]  1.820848e-01-3.2090e-06i
> [25032,]  1.820848e-01-3.2090e-06i
> [25033,]  1.820848e-01-3.2090e-06i
>
> Any general idea what may be going on here?

Those are all complex numbers.

>
> It is a sporadic problem... it occurs maybe 2% or 3% of the time  
> when running this particular script on various data.

You are most likely "solving" or inverting <something> that does not  
have all real roots or eigenvalues  ... or something.

>
> I apologize for not including a pared-down example that reproduces  
> the problem.... we are using an R script written elsewhere on large  
> data sets.  If someone wants more specifics please follow up.
>
> Steve Grubb


David Winsemius, MD
Heritage Laboratories
West Hartford, CT