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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='color:#1F497D'>Everyone,<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I found a work-around for my problem.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>I ended up modifying the grads source code and enabling ‘set clip’ for the ‘display’ command.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>(by default, ‘set clip’ only works for ‘draw’ commands, but not for ‘display’ commands)<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>This allowed me to define a clipping region using ‘set clip’, display a variable, and have the resulting contour plot be drawn only within the clipping region.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>‘set clip x1 x2 y1 y2’<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>‘display const(A,0,-u)’<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>… and const(A) will only be drawn within the clipping regioned defined by ‘x1 x2 y1 y2’.<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Regards,<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'>Pablo<o:p></o:p></span></p><p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'><p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> gradsusr-bounces@gradsusr.org [mailto:gradsusr-bounces@gradsusr.org] <b>On Behalf Of </b>pr<br><b>Sent:</b> Friday, January 14, 2011 11:28 PM<br><b>To:</b> 'GrADS Users Forum'<br><b>Subject:</b> [gradsusr] use 'const' only over a specific region<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Hi,<o:p></o:p></p><p class=MsoNormal>I don’t know if the following is possible, and I need help…<o:p></o:p></p><p class=MsoNormal>I need to use the ‘const’ function for a variable, but ONLY over a specific region…<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Here’s the problem:<o:p></o:p></p><p class=MsoNormal>I have two variables, A & B<o:p></o:p></p><p class=MsoNormal>Variable A is from a dataset with a global 0.5x0.5 grid, yet it has all undefined values over the region covering the Mediterranean Sea.<o:p></o:p></p><p class=MsoNormal>Variable B is from a separate dataset with a 0.167x0.167 resolution that covers the Med. Sea area and also a small portion of the Atlantic (over the Bay of Biscay near France).<o:p></o:p></p><p class=MsoNormal>What I want to do is:<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>1)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>First plot variable A from the global dataset using const to fill in all undefined areas<o:p></o:p></p><p class=MsoListParagraph>‘d const(A,0,-u)’<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo2'><![if !supportLists]><span style='mso-list:Ignore'>2)<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]>Overlay variable B from the regional dataset onto the global plot of A & ALSO use const to fill in areas with undefined values.<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'>‘d const(B,0,-u)’ , plot ‘const(B) only over the Mediterranean region<o:p></o:p></p><p class=MsoNormal style='margin-left:.5in'><o:p> </o:p></p><p class=MsoNormal>The problem is that the 2<sup>nd</sup> display command, ‘d const(B,0,-u)’, overwrites the plotting from the first display command, so everything outside variable B’s region is set to a value of ‘0’.<o:p></o:p></p><p class=MsoNormal>I thought about trying to somehow ‘merge’ or ‘add’ the two variables, such as ‘display const(A+B,0,-u)’, but this doesn’t work since the datasets have different sized grids & different resolutions.<o:p></o:p></p><p class=MsoNormal>(I’d really like to avoid having to over-complicate things by having to use regrid and create new grids or merge datasets.)<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>…Although I know that this is currently not supported, ideally, I’d like to do something like the following:<o:p></o:p></p><p class=MsoNormal><i>* plot const(A) over entire grid (i.e.,globally)<o:p></o:p></i></p><p class=MsoNormal><b>‘display const(A,0,-u)’<o:p></o:p></b></p><p class=MsoNormal><i><o:p> </o:p></i></p><p class=MsoNormal><i>* now display const(B), overlaying onto previous plot of ‘const(A)’ <o:p></o:p></i></p><p class=MsoNormal><i>* cropping results of ‘const(B)’ so that it ONLY covers the Med. Sea region<o:p></o:p></i></p><p class=MsoNormal><b>‘display const(B,0,-u,lon1=-5.6,lat1=30,lon2=42,lat2=47)<o:p></o:p></b></p><p class=MsoNormal><i><o:p> </o:p></i></p><p class=MsoNormal><i>* Now, handle ‘Bay of Biscay’ region, since it was overwritten by ‘const(B)’<o:p></o:p></i></p><p class=MsoNormal><i>* So, re-plot const(A) over this small region<o:p></o:p></i></p><p class=MsoNormal><b>‘display const(A,0,-u,lon1=-5.6,lat1=43,lon2=0,lat2=47)<o:p></o:p></b></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Would it be feasible to modify the source code for ‘const’ in order to achieve the ‘regional cropping’ of const that Ive shown in the example above?<o:p></o:p></p><p class=MsoNormal>Or, Can my goal be achieved using some combination of ‘const’, ‘maskout’, ‘set clip’, or some other function(s)?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Please help,<o:p></o:p></p><p class=MsoNormal>Thanks,<o:p></o:p></p><p class=MsoNormal>Pablo<o:p></o:p></p></div></body></html>