Hi, I obtained some netcdf data from NCEP website (attached here). It contains gridded geopotential heights at 1 level with 9 lats and 13 lons, and 489 time steps (so the dimension is 489 1 9 13). The website could plot the data into contour lines (see attached figure). I wonder whether R has certain functions dedicated to produce similar plot for such weather variables. Thanks! Linda -------------- next part -------------- A non-text attachment was scrubbed... Name: geopotentialheight.png Type: image/png Size: 10036 bytes Desc: not available URL: <https://stat.ethz.ch/pipermail/r-help/attachments/20100428/fefe4ec2/attachment.png>