As shown in the code, the extraction of NDVI, floating point overflow error occurred, and a great god teach

 
ENVI_FILE_QUERY, fid, DIMS=DIMS 
ENVI_DOIT, 'NDVI_DOIT, $
FID=FID, $
=DIMS DIMS, $
POS=(3, 2], $
/check, $
OUT_DT=4, $
OUT_NAME=outFile 

With! Except, tracking and error is: the Program under caused arithmetic error: Floating overflow
% Detected at NDVI_DOIT 47