eof_4 example error

Hi dear there,

I am trying eof_4 example (http://www.ncl.ucar.edu/Applications/eof.shtml)
which focuses on computing EOFs; normalizing the principal components; and
projecting the anomalies via regression to compute the Antarctic
Oscillation (AAO). I downloaded the geopotential height data and placed it
in the directory I am working on.

However, it gives me the error messages below. I would highly appreciate
your help.

Warning! LAPACK routine returned eigenvalue <= 0.
 Setting it to zero...

warning:ContourPlotInitialize: no valid values in scalar field; ContourPlot
not possible:[errno=1101]
warning:ContourPlotSetValues: Invalid level values set: using
AUTOMATICLEVELS mode
warning:ContourPlotSetValues: Data values out of range of levels set by
MANUALLEVELS mode
warning:ContourPlotSetValues: cnLevelSpacingF value exceeds or equals data
range: defaulting
(0) gsn_csm_xy: Fatal: There are no values above or below the chosen
reference line.
(0) Cannot draw a bar chart

Received on Tue Jul 22 01:20:58 2014