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 Post subject: Hourly pressure change.
PostPosted: Mon Jan 24, 2005 7:18 am 
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Junior Member

Joined: Mon Jan 10, 2005 4:58 pm
Posts: 8
Location: Memphis TN
Good day.
I am trying to get a chart that shows the pressure change between two consecutive hours with positive numbers blue and negative numbers in red and max and min points. The desired end result would be a chart that shows just the pressure change. But the slpr for the current hour is drawn also. How do I get the script to plot just the pressure change.

The following is the script I have come up with.
download,http://weather.cod.edu/digatmos/sao/@Y@M@D$H.sao,c:\Program files\DigitalAtmosphereWS\data\temp.dat
ingest,c:\Program files\DigitalAtmosphereWS\data\temp.dat
analyze,stor=1 cont slpr hsfc
erase
download,[url]http://weather.cod.edu/digatmos/sao/@Y@M@D@H.sao,c:\Program[/url] files\DigitalAtmosphereWS\data\temp.dat
ingest,c:\Program files\DigitalAtmosphereWS\data\temp.dat
analyze,stor=2 cont slpr hsfc
erase
analyze,mxmn cont cint=4 line=2 color=0:0:180 grtn=0 cont cint=4 line=2 color=200:0:0 lstn=0 sdif=1:2

Thank you


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 Post subject:
PostPosted: Mon Jan 24, 2005 8:03 am 
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Senior Member

Joined: Tue Nov 25, 2003 4:22 pm
Posts: 198
Location: Suoi Tien, Vietnam
Hello

Very nice script. The $H is new for me. I could not find it in the manual (but it's rather early here).
When I run the script I get 1 long line and 2 short + some X and N. I don't see the SLPR. Only when I add a space after the second erase I see a lot of lines. Is this what you mean? Can you place a map on the forum or send it to me? Then I know exactly what you have.

Greetings

Fred


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 Post subject:
PostPosted: Mon Jan 24, 2005 8:19 pm 
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Senior Member

Joined: Fri Dec 12, 2003 9:42 pm
Posts: 155
To my knowledge, manipulations across different data files are not possible, so the only way to plot pressure tendency is to extract it from the synoptic observations.

I could be wrong though, you may want to ask Tim about it.

Bob


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 Post subject:
PostPosted: Tue Jan 25, 2005 3:14 am 
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Junior Member

Joined: Mon Jan 10, 2005 4:58 pm
Posts: 8
Location: Memphis TN
The $h is for the last hours data.

Bob, I think this script makes it possible to plot pressure changes between two consecutive hours. As of yet, I have not verified the results but am just testing it. Any feed back is welcome.
I would like to post the results but am not able to get them to show up here.
Thanks


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 Post subject:
PostPosted: Tue Jan 25, 2005 4:55 am 
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Joined: Tue Nov 25, 2003 4:22 pm
Posts: 198
Location: Suoi Tien, Vietnam
Just a quick reaction before I go to my work. My first results looks very good, although not tested in detail. I made one with coloured bands, only the negative is not good yet. Later more with the whole script.

Greetings

Fred


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 Post subject:
PostPosted: Thu Jan 27, 2005 8:49 am 
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Senior Member

Joined: Tue Nov 25, 2003 4:22 pm
Posts: 198
Location: Suoi Tien, Vietnam
Tim

Trying to modify the above script I faced again the problem of the negative values.
Using the command "..... equa=-2 sdif=1:2" does not give a result. I tried the command in a lot of different ways but nothing works. To be sure, is it a bug in the program or do I make mistakes in the syntax?

Although adding a value to it and ask for the positive value works sometimes it often causes other problems and makes the script very complex. I (and many others) hope that -if it is a bug- it can be solved in the next release.

Greetings

Fred


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 Post subject:
PostPosted: Thu Jan 27, 2005 3:45 pm 
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Junior Member

Joined: Mon Jan 10, 2005 4:58 pm
Posts: 8
Location: Memphis TN
Tim, thanks for the help.

I have been looking at the results and overall it looks promising. The positive side looks the best and I agree that the negative side looks suspect. I would be intrested in seeing your modifications to the script to see how you did it.

I did have a space after the second erase.
Thanks again.


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 Post subject:
PostPosted: Thu Jan 27, 2005 7:04 pm 
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Senior Member

Joined: Tue Nov 25, 2003 4:22 pm
Posts: 198
Location: Suoi Tien, Vietnam
Hello

I continued testing my script and I found some more strange things.
For a value 2 the command GRTN=1 gives the requested colour, while EQUA=2 gives a white fill: nothing happens!
Or the EQUA command does not work or asking =2 is perhaps not correct. This also because of the second problem. If I ask LSTN=0 I expect everything starting with -1. I also get 0. Looking to the N I can see a "-0" displayed in it. But as I stated in my previous post, asking for - does not work.

What now??

Greetings

Fred


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 Post subject:
PostPosted: Tue Feb 01, 2005 7:50 am 
The last time I ran the script I looked at stor=1 and compared it to stor=2 and they were the same. :?: :?:
Then I took it apart and ran each part seperaty. Past hours data was saved all right and was correct. The current hours data also was saved corectly. I plotted one over the other and then ran the third part, the sdif=1:2. I devided the result into three parts and then contured each part seperately. This result was the isopleths were reversed those that were lstn=0 were plotted where the grtn=0 was supposed to be and visa-versa. This was confermed I contured equa=0 in a third color. Both sides plotted the 0 line. What I do not know is if the program findes the differance graphicly or mathamaticly, or it just does not know what to do.
I was wondering if sdif=2:1 would work.

I do not know what is going on with this and hopeing that Tim might beable to give some insites to the problem.

:idea: An idea just accured to me to runit with temperatures and see what happens. I will let you know.


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 Post subject:
PostPosted: Sat Feb 05, 2005 9:04 pm 
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Junior Member

Joined: Mon Jan 10, 2005 4:58 pm
Posts: 8
Location: Memphis TN
Every time I run this script I get a different results. I think there is a bug in the program. I am going to put this on the back burner for now.
Thanks for the help.

I was the "Guest" for the last post.


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