>From: "Paul L. Sirvatka" <address@hidden> >Organization: College of DuPage >Keywords: 200102162013.f1GKD9L01250 McIDAS-X SFCCON GRDDISP Paul, >OK....here is the program that should work. OK, I'll take a look. >IGU DEL 21 >EG 4 6 > > >SFCCON MIX SURFACEMAP LATEST OUT=SAVE MYDATA/GRIDS.21 >SFCCON STREAML SURFACEMAP LATEST OUT=SAVE MYDATA/GRIDS.21 > >REM This is Moisture FLux Divergence >GRDDISP MYDATA/GRIDS.21 4 MAP=SURFACEMAP G1='PARAM MIX' G2='PARAM U' >G3='PARAM V' NEWPAR=MDVG GKGS SFC >MATH='(G1*(DDX(G2)+DDY(G3))+G2*(DDX(G1))+G3*(DDY(G1))*36000)'CINT=2 >DASH=POS FORMAT=F4 > >REM This is moisture advection >GRDDISP MYDATA/GRIDS.21 5 MAP=SURFACEMAP G1='PARAM MIX' G2='PARAM U' >G3='PARAM V' NEWPAR=MADV GKGH SFC MATH='((G2*DDX(G1) + G3*DDY(G1))*36000)' >DASH=POS CINT=2 FORMAT=F4 > >REM This is moisture*divergence >GRDDISP MYDATA/GRIDS.21 6 MAP=SURFACEMAP G1='PARAM MIX' G2='PARAM U' >G3='PARAM V' NEWPAR=MDIV GKGH SFC MATH='((G1*(DDX(G2) + DDY(G3)))*36000)' >DASH=POS CINT=2 FORMAT=F4 >The first one is the definition of Moisture flus divergence which is a sum >of moisture advection and moisture time divergence. > >When you run this...I would guess that it is frame 4 = fr 5 + fr 6. >It is not. And I do not know why the answers are so different! I copied your script into a file (TEST.BAT) in my McIDAS working directory and then ran it. I agree that 'frame 4 = fr 5 + fr 6' should be the result, but is not. I took a harder look at your first function and I think I see the problem: MATH= from equation 1: (G1*(DDX(G2)+DDY(G3))+G2*(DDX(G1))+G3*(DDY(G1))*36000) Splitting the terms out, we get: G1*(DDX(G2)+DDY(G3)) G2*(DDX(G1))+G3*(DDY(G1))*36000 Note that the 36000 is multiplying G3*(DDY(G1)) _only_. Somewhere one or more parentheses got dropped. MATH= from equation 2 is: ((G2*DDX(G1) + G3*DDY(G1))*36000) In this, 36000 multiplies the sum of (G2*DDX(G1) + G3*DDY(G1)) MATH= from equation 3 is: ((G1*(DDX(G2) + DDY(G3)))*36000) In this, 36000 multiplies the sum of (G1*(DDX(G2) + DDY(G3))) So, I think that the MATH= in equation 1 should be: ((G1*(DDX(G2)+DDY(G3))+G2*DDX(G1)+G3*DDY(G1))*36000) I made this change and I think I get 'frame 4 = fr 5 + fr 6'. Please make the same change in your script; run it; and let me know if you don't agree. >Also...this is not the same that MCIDAS with MDVG from SFCPLT works. Let's revisit this after you update the MATH= clause in your script and rerun it. >I am very frustrated now. Can you help? I hope that your problem was one or more missing parentheses. >Also...i keep losing my image window. Is it a bug in McIDAS or in my >x-windows. Can you tell me how this happens? Is something in particular running when it happens? If so, what? I think that it might be a problem in Xwindows, but it might be a program crapping out. I found one such bug in McIDAS-X 7.6 and fixed it some time ago. >Also how do you see the end of the lines with > at the end? You have two options for the Text and Command window: o grab either side with the mouse and make the window wider o you can use the ALT-] key sequence to scroll the Text and Command window contents to the right and the ALT-[ key sequence to scroll to the left >Thanks What operating system are you running on? Also, what version of McIDAS are you using? I ask so that I can better contemplate the image window disappearance problem. Tom
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