Read XieArkin's precipitation data by ddf file

[Ji-Yun SEO]

Hi ^^ HAPPY NEW YEAR!!

I've been trying to draw a XieArkin's precipitation data netcdf file.
when i downloaded it there is a referencing page to read these data using
a Grads .ddf file
Unfortunately, i coulnd't read it properly although i followed the
direction.
this's my prec.ddf file

DSET ^XieArkin-1979-2002.nc
*UNDEF 1E36
UNDEF -999.f
XDEF lon 144 Linear 0.0 2.5
YDEF lat 73 Linear -90. 2.5
TDEF time 288 Linear Jan1979 1mo
VARS 1
PRC2 => prc2 1 99 Precipitation
ENDVARS

i did gradsnc ; sdfopen prec.ddf
but this error message comes out

scanning self-describing file:  prec.ddf
prec.ddf does not exist or is not a netCDF file.

Couldn't ingest SDF metadata.
If this was an HDF-SDS file, try gradshdf.

please help me
i would be grateful if i get any advice from you guys!!!