textread() barfs silently when file contains "nan" or "inf"

[Rob Mahurin]

running octave 3.0.1.

file "bug.txt" contains
0.090   015.0   013.9   20.456  15.3822 60.7908
0.088   015.0   NaN     20.486  15.3438 60.7438
0.086   015.0   013.8   20.494  15.2289 60.5916

from octave:
[c1,c2,c3,c4,c5,c6] = textread("bug.txt","%f %f %f %f %f %f");
[c1,c2,c3,c4,c5,c6]
ans =

     0.090000   15.000000   13.900000   20.456000   15.382200    
60.790800
     0.088000   15.000000   15.000000   15.000000   15.000000    
15.000000
     0.086000   15.000000   13.800000   20.494000   15.228900    
60.591600

So, reading "nan" or "inf" (or other invalid input) stops processing  
for the current line without throwing an error.

Quick fix: detect and complain about error
Better fix: support nan and inf, document

I forget whether textread() is an octave-forge function, and whether  
this is the right mailing list if so.  Sorry.

Cheers,
Rob

-- 
Rob Mahurin
Dept. of Physics & Astronomy
University of Tennessee 	phone: 865 207 2594
Knoxville, TN 37996     	email: rob at utk.edu