<br>The data projection is Lambert Conformal with central meridian of 265 and reference latitude of 25.<br><br>It's a GRIB 2 data set, but there are some characters before 'GRIB' key word. In my opinion, a standard GRIB data file should be start with 'GRIB'. My question is if it is a standard GRIB data file?<br>
<br><div class="gmail_quote">On Thu, Jan 5, 2012 at 7:20 AM, Jennifer Adams <span dir="ltr"><<a href="mailto:jma@cola.iges.org">jma@cola.iges.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div style="word-wrap:break-word"><div>Jeff, </div><div><div><br><div><div class="im"><div>On Jan 4, 2012, at 12:19 PM, Jeff Lake wrote:</div><br><blockquote type="cite"><div>This is exactly the problem ...<br>the dbf is also in a format I nor GDAL has ever seen before,<br>
</div></blockquote></div>In GrADS, you can issue the 'q dbf' command and it will spew the contents of the dbf file. The utility 'dbfdump', which comes with the shapefile library, also has no trouble reading the dbf file. There is very little structure to the dbf file, it's just a list of attributes and the values that go with them for each element in the file. </div>
<div><br></div><div><div class="im"><blockquote type="cite"><div>could be this temp, but yet it could be this???<br></div></blockquote></div>I'm sorry, but I don't understand this statement. </div><div><div class="im">
<br><blockquote type="cite"><div><br>this is the GRIB file I'm using<br><a href="http://weather.noaa.gov/pub/SL.us008001/ST.opnl/DF.gr2/DC.ndgd/GT.rtma/AR.conus/RT.01/ds.temp.bin" target="_blank">http://weather.noaa.gov/pub/SL.us008001/ST.opnl/DF.gr2/DC.ndgd/GT.rtma/AR.conus/RT.01/ds.temp.bin</a><br>
<br>the RT.01 determines the cycle hour<br><br>GrADS version 2.0.1,<br>CentOS 5.7 64bit<br><br><br>and the script snippet<br><br>'clear shp'<br>'set lat 20 55'<br>'set lon -150 -45'<br>'set gxout shp'<br>
'set mproj latlon'<br>'set ccols 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22'<br>'set clevs -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 <br>55 60 65 70 75 80 85 90 95 100 105 110 115 120 125 130 135'<br>
'set shp -poly rtma_temp'<br>'d (TMP2m-273.16)*9/5+32'<br>'quit'<br></div></blockquote><div><br></div></div><div>I grabbed the file, used g2ctl, and drew a grfill plot with GrADS, overlaying a shapefile with the state boundaries (instead of the default map plotted by GrADS). Here is the result:</div>
<div><img src="cid:0DAC4AE9-CF43-4B75-92D1-B3E0FD3A11D6@SME" height="670" width="829"></div><div>Next I used 'gxout shp' and created a shapfile based on this data. Then I import the shapefile I created into Qgis and draw it using no outline and coloring in the polygons according to the classification field MIN_VALUE and then overlay the same shapefile (statesp020) and get this: </div>
<div><br></div><div><img src="cid:747F0C3F-64E0-4D60-BA8A-8B86C7D53338@SME" height="448" width="839"></div><div><br></div><div>There is no re-projecting going on, the plots are the same, other than the color scheme -- it's a pain to define colors in Qgis, so I used this blue/green palette. As far as I can tell, there is nothing wrong with the shapefile created by GrADS. </div>
<div class="im"><blockquote type="cite"><div><br><br>I would let GrADS do my mapping, but I'm some what of a stickler about <br>my maps looking the same<br>I cannot for the life of me get GrADS to match my projection<br>
<a href="http://contours.michiganwxsystem.com/forecasts/gfs/gfsmos_d1_maxt.png" target="_blank">http://contours.michiganwxsystem.com/forecasts/gfs/gfsmos_d1_maxt.png</a><br>I got GEMPAK to match (and they say that is harder), but not GrADS :(<br>
</div></blockquote><div><br></div></div><div>As for the projection in your michiganwxsystem plot, it doesn't appear to be drawn with GrADS, but it looks like a polar stereographic projection. In GrADS, use 'set mproj nps' and then display your temperature plot and it will look like this: </div>
<div><br></div><div><img src="cid:84A79D0C-5690-4F52-97BE-B6AD61B23D1C@SME" height="360" width="638"></div><div><br></div><div><br></div><div>This looks like the projection in the image on your website. As for getting Qgis to draw in a polar stereographic projection … I have no idea how to do this. Perhaps this is another user in the forum who will know. </div>
<span class="HOEnZb"><font color="#888888"><div>--Jennifer</div></font></span><div><div class="h5"><div><br></div><blockquote type="cite"><div><br>-Jeff Lake<br><a href="http://MichiganWxSystem.com" target="_blank">MichiganWxSystem.com</a><br>
WeatherMichigan.net<br>TheWeatherCenter.net<br>GRLevelXStuff.com<br><br><br>On 1/3/2012 7:43 PM, Yaqiang Wang wrote:<br><blockquote type="cite">It seems GrADS does not form real 'polygon' from contour lines by<br>
</blockquote><blockquote type="cite">topology analysis. This is the source of the problem.<br></blockquote><blockquote type="cite"><br></blockquote><blockquote type="cite">On Wed, Jan 4, 2012 at 7:17 AM, Jennifer Adams<<a href="mailto:jma@cola.iges.org" target="_blank">jma@cola.iges.org</a>> wrote:<br>
</blockquote><blockquote type="cite"><blockquote type="cite">Jeff,<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">The shapfile interface in GrADS creates a shapefile that contains polygons<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">that fill out the areas outlined by the shaded contours. Because of the<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
rules in the shapefile spec regarding polygon geometry, the area inside a<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">shaded contour is split up into many pieces so that individual polygons do<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">not overlap and do not contain holes (no donuts). That is why you are seeing<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
all the vertical lines. If you color in the polygons and use the same color<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">to draw the outline, you won't see the vertical lines and the plot will look<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">more normal (like the shaded contour plot in GrADS).<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote>
</blockquote><blockquote type="cite"><blockquote type="cite">Also, before you create the shapefile, you must be in the latlon projection<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">(set mproj latlon). No other projection will work. It should be possible to<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">use your GIS tool to re-project the data in the shapefile using the metadata<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
in the file provided by GrADS. From the attachement you sent, it's difficult<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">to tell what the problem is -- better to draw a plot of a variable such a<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">land mask that would clearly show whether the boundaries in the data are<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
lining up with the political boundaries (and color them in and use matching<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">outline color). If there is an issue in the way Qgis is re-projecting the<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">shapefile, then that may or may not be a GrADS problem.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote>
</blockquote><blockquote type="cite"><blockquote type="cite">The polygons 'connect to the outside' because they are filling in the<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">lat/lon block defined by your dimension environment. You can't mask your<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">shapefile according to political boundaries, but you can choose to not draw<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
a certain contour level by using -1 instead of a color number in the 'set<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">ccols' command.<br></blockquote></blockquote><blockquote type="cite">
<blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">I can't help you any further without more specific information about what<br></blockquote></blockquote><blockquote type="cite">
<blockquote type="cite">version of GrADS you're using, what the descriptor file looks like for your<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">data, the source of your data file (so I can grab a sample), what your<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">commands were to generate the shapefile, and what you did inside Qgis to<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
create the display in your attachment.<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">--Jennifer<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote>
</blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">On Jan 3, 2012, at 4:22 PM, Jeff Lake wrote:<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote>
<blockquote type="cite"><blockquote type="cite">I believe there is a minor, okay major, flaw in the conversion to shape file<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">here is the shape file I get when converting the RTMA GRIB over (see<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">attachment)<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">the resulting polygons all 'connect' to the outside<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">this is a cint set from -30 to 140 by 5 degree's<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">this is a better result then another piece of software, but still not<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">correct..<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">
anybody got suggestions ??<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite"><br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">--<br></blockquote></blockquote><blockquote type="cite">
<blockquote type="cite">-Jeff Lake<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">MichiganWxSystem.com<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">WeatherMichigan.net<br>
</blockquote></blockquote><blockquote type="cite"><blockquote type="cite">TheWeatherCenter.net<br></blockquote></blockquote><blockquote type="cite"><blockquote type="cite">GRLevelXStuff.com<br></blockquote></blockquote><blockquote type="cite">
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