Length of a poly line...

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ianw2
Posts: 139
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Location: Temecula, California
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Length of a poly line...

Post by ianw2 » Sun Jul 10, 2005 11:48 am

Is there anyway to determine the length of a polyline? I have a countour map and need to determine the lengths of the countour lines for a rather odd formula used by San Diego County to calculate the average slope of a parcel of land.

The formula uses the total lengths of the contour lies, the interval between them and the area of the parcel to determine the average slope.

Thanks in advance!
Ian Wilson
Ian Wilson Land Surveying, Inc.
Temecula CA 92591
(951) 684-1044

Richard Sands
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Location: Tasmania

LENGTH OF POLYLINE

Post by Richard Sands » Sun Jul 10, 2005 6:43 pm

Ian
Just type AREA and select the polyline - it gives an area that doesn't mean much and the length.
Richard

rwhatman
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Joined: Sun Nov 10, 2002 6:41 am
Location: Peterborough, Ontario, Canada

Post by rwhatman » Mon Jul 11, 2005 3:13 am

Some Contour lines are Smoothed. You will get the wrong Lenght if you pick on a Smoothed Contour.

Just un-smooth it and the then use the AREA command. You will get then get the right answer.

The Area command does work on Curved polylines, just not Smooth polylines, because they are no longer Polylines.

ianw2
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Joined: Sun Nov 24, 2002 6:45 am
Location: Temecula, California
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Post by ianw2 » Mon Jul 11, 2005 6:08 am

Thank you, gentlemen!

What a board!
Ian Wilson
Ian Wilson Land Surveying, Inc.
Temecula CA 92591
(951) 684-1044

ianw2
Posts: 139
Joined: Sun Nov 24, 2002 6:45 am
Location: Temecula, California
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Post by ianw2 » Mon Jul 11, 2005 3:40 pm

Unfortunately, the AREA command is a point ot point function.

What I ended up doing was closing the countour polylines with a line, using the Fast Area command, blowing off all that data and issuing a PERIMETER command. By subtracting the length of the closing line from the PERIMETER data, I get the length of the contour line. WOOF! Involved, but it does the trick.

San Diego Couty uses the following formula to determine average slope of a parcel:

S = (I * L * 100) / (A * 43560)

where,
S = Average Slope
I = contour interval
L = length of contour lines through parcel
A = Area of parcel in acres.

I don;t knopw if it's possible, but I vote for a routine to get the length of the contour lines (or any polyline). That would seriously help with such foolishness.

Thanks for the help, though!
Ian Wilson
Ian Wilson Land Surveying, Inc.
Temecula CA 92591
(951) 684-1044

rwhatman
Posts: 299
Joined: Sun Nov 10, 2002 6:41 am
Location: Peterborough, Ontario, Canada

Post by rwhatman » Tue Jul 12, 2005 3:46 am

If you had picked the option Object that would have given you the Lenght of that polyline.

ianw2
Posts: 139
Joined: Sun Nov 24, 2002 6:45 am
Location: Temecula, California
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Post by ianw2 » Tue Jul 12, 2005 3:32 pm

OK! So my mother was a really good gardner! She got her vegetables to talk and be land surveyors! ;^)

Oh, you mean THAT "OBJECT"!

Boy, do I feel :oops:

Ah...thanks Mr. rwhatman!

For that, if you send me your mailing address, I'll send you an Ian Wilson Land Surveying, Inc. cap (the 2005 edition, too!)
Ian Wilson
Ian Wilson Land Surveying, Inc.
Temecula CA 92591
(951) 684-1044

Glen Cameron
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Cap

Post by Glen Cameron » Tue Jul 12, 2005 6:52 pm

I helped teach Richard everything he knows (well not everything but I did help him many times), so can I get one of the elite caps too? :)

Cheers,
Glen W. Cameron, C.E.T.
City of North Bay, Ontario

rwhatman
Posts: 299
Joined: Sun Nov 10, 2002 6:41 am
Location: Peterborough, Ontario, Canada

Re: Cap

Post by rwhatman » Wed Jul 13, 2005 9:31 am

Glen W. Cameron, C.E.T. wrote:I helped teach Richard everything he knows (well not everything but I did help him many times), so can I get one of the elite caps too? :)

Cheers,
Yep Glen has been a big help over the years.

I have had help from many at MicroSurvey.

Jason, Darcy and a few others that I can't think of there names right now.

If you have a spare Cap send Glen one.

ianw2
Posts: 139
Joined: Sun Nov 24, 2002 6:45 am
Location: Temecula, California
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Post by ianw2 » Wed Jul 13, 2005 9:35 am

Don't worry (be happy)! The cap is already wending its way to Glen, even as we speak!

Jason was my first contact with MSCAD way back when HE first started with MicroSurvey. Had it not been for his help and tutelage, I wouldn't be using the product.

Darcy, although presidentof the company, has been a big help over the years, too! Where else can you get such a great tool AND be able to call up and talk to the president of the company like the old friend he is?

As far as Glen, well, what the heck can you say about Glen? Who else monitors this board (or any other) and his emails the same way or with the same style? I couldn't even begin to count the number of times Glen has been there with a tip, suggest or outright help!

Of course, then there's the other users, too! What a bunch! You can get five work arounds or suggestions within 24 hours from people who are really using the product (not people who have never heard of surveying and are reading some bloody script off a page)!
Ian Wilson
Ian Wilson Land Surveying, Inc.
Temecula CA 92591
(951) 684-1044

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