need help - problem viewing U.S. map; how to add data

[roger.taylor]

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I have opened a shape file of the U.S. showing U.S. Congressional Districts. Alaska does not appear correctly in the Map View window of Quantum GIS. I have previously opened this file using ArcGIS without this problem. Here is the link to the file I’m using:

http://nationalatlas.gov/atlasftp.html#cgd110p

 

The title is “Congressional Districts of the United States - 110th Congress” and the zip file is cgd110p020.tar.gz.

 

So, does anyone know why Alaska does not look right? I need to be able to work with this file as part of an important job assignment.

 

My second question: How do I add a new field and populate it efficiently? I would like to add the voting results for a bill to the above shape file dataset. There are 1000’s of features in this file, since there are many more land forms than there are districts. So efficiently putting in a “yea” or “nay” in the vote column is going to require a good method.

 

As you can tell, I am a novice w/ GIS.

 

Thanks,

 

Roger

 

 

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[MS-14]

When you say Alaska does not appear correctly in the Map View, are you
saying that the shape is distorted?  If yes, then the problem likely
lies with the projection.

Mark

On Feb 12, 2008 11:45 AM,  <roger.taylor@...> wrote:

>
>
>
>
> I have opened a shape file of the U.S. showing U.S. Congressional Districts.
> Alaska does not appear correctly in the Map View window of Quantum GIS. I
> have previously opened this file using ArcGIS without this problem. Here is
> the link to the file I'm using:
>
> http://nationalatlas.gov/atlasftp.html#cgd110p
>
>
>
> The title is "Congressional Districts of the United States - 110th Congress"
> and the zip file is cgd110p020.tar.gz.
>
>
>
> So, does anyone know why Alaska does not look right? I need to be able to
> work with this file as part of an important job assignment.
>
>
>
> My second question: How do I add a new field and populate it efficiently? I
> would like to add the voting results for a bill to the above shape file
> dataset. There are 1000's of features in this file, since there are many
> more land forms than there are districts. So efficiently putting in a "yea"
> or "nay" in the vote column is going to require a good method.
>
>
>
> As you can tell, I am a novice w/ GIS.
>
>
>
> Thanks,
>
>
>
> Roger
>
>
>
>
> _______________________________________________
> Qgis-user mailing list
> Qgis-user@...
> http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
>
>

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[roger.taylor]

Good question! There is no distortion but rather the Alaska mainland
does not show up at all. All the islands around Alaska show up, however.
In addition there is a shape next to the eastern border of Alaska that
is not a state at all.

-----Original Message-----
From: M S [mailto:mseibel@...]
Sent: Tuesday, February 12, 2008 12:03 PM
To: Taylor, Roger @ SYColeman
Cc: qgis-user@...
Subject: Re: [Qgis-user] need help - problem viewing U.S. map; how to
add data

When you say Alaska does not appear correctly in the Map View, are you
saying that the shape is distorted?  If yes, then the problem likely
lies with the projection.

Mark

On Feb 12, 2008 11:45 AM,  <roger.taylor@...> wrote:
>
>
>
>
> I have opened a shape file of the U.S. showing U.S. Congressional
Districts.
> Alaska does not appear correctly in the Map View window of Quantum
GIS. I
> have previously opened this file using ArcGIS without this problem.
Here is
> the link to the file I'm using:
>
> http://nationalatlas.gov/atlasftp.html#cgd110p
>
>
>
> The title is "Congressional Districts of the United States - 110th
Congress"
> and the zip file is cgd110p020.tar.gz.
>
>
>
> So, does anyone know why Alaska does not look right? I need to be able
to
> work with this file as part of an important job assignment.
>
>
>
> My second question: How do I add a new field and populate it
efficiently? I
> would like to add the voting results for a bill to the above shape
file
> dataset. There are 1000's of features in this file, since there are
many
> more land forms than there are districts. So efficiently putting in a
"yea"

> or "nay" in the vote column is going to require a good method.
>
>
>
> As you can tell, I am a novice w/ GIS.
>
>
>
> Thanks,
>
>
>
> Roger
>
>
>
>
> _______________________________________________
> Qgis-user mailing list
> Qgis-user@...
> http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
>
>

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Qgis-user@...
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[MS-14]

I verified what you are experiencing.  Here is what I tried, and some
things I observed.

*  The polygon can be queried with the "identify tool", but it is not
drawing the geometry correctly at scales smaller than 1:6.
*  Reprojected the dataset to something more localized for Alaska (UTM
zone 6).  Still got the odd shape.
*  Extracted and drew only that polygon ("ID" = 3407) and still got
odd geometry.
*  Converted the shapefile to a mapinfo file, and got the same odd geometry
*  Verified that the data draws ok in other GIS software.
*  Zooming in to a scale of 1:6, the polygon draws where it appears
white/empty at scales smaller than this.
*  Imported into GRASS the single AK polygon which was extracted
previously with ogr2ogr.  File imports into GRASS with the same odd
shape.

Maybe it is a bad shapefile, specifically along the northern edge of
Alaska, where the shape seems to "flip" about the northern boundary
line.  I did downloaded and draw the 109th congress data file, and it
displayed the same erroneous shape; however, I wonder if 109 and 110
could be from the same geometry source, but contain different
attributes.

Interestingly enough, from the same webpage, I then downloaded the
1980 county boundaries shapefile (same projection), and QGIS drew
Alaska without any of those issues.

Not sure how much that really helps, but I tried.

Mark

On Feb 12, 2008 11:45 AM,  <roger.taylor@...> wrote:

>
>
>
>
> I have opened a shape file of the U.S. showing U.S. Congressional Districts.
> Alaska does not appear correctly in the Map View window of Quantum GIS. I
> have previously opened this file using ArcGIS without this problem. Here is
> the link to the file I'm using:
>
> http://nationalatlas.gov/atlasftp.html#cgd110p
>
>
>
> The title is "Congressional Districts of the United States - 110th Congress"
> and the zip file is cgd110p020.tar.gz.
>
>
>
> So, does anyone know why Alaska does not look right? I need to be able to
> work with this file as part of an important job assignment.
>
>
>
> My second question: How do I add a new field and populate it efficiently? I
> would like to add the voting results for a bill to the above shape file
> dataset. There are 1000's of features in this file, since there are many
> more land forms than there are districts. So efficiently putting in a "yea"
> or "nay" in the vote column is going to require a good method.
>
>
>
> As you can tell, I am a novice w/ GIS.
>
>
>
> Thanks,
>
>
>
> Roger
>
>
>
>
> _______________________________________________
> Qgis-user mailing list
> Qgis-user@...
> http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user
>
>

_______________________________________________
Qgis-user mailing list
Qgis-user@...
http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user

[gsherman]

On Feb 12, 2008, at 7:45 AM, roger.taylor@... wrote:

> I have opened a shape file of the U.S. showing U.S. Congressional  
> Districts. Alaska does not appear correctly in the Map View window  
> of Quantum GIS. I have previously opened this file using ArcGIS  
> without this problem. Here is the link to the file I’m using:
> http://nationalatlas.gov/atlasftp.html#cgd110p
>
> The title is “Congressional Districts of the United States - 110th  
> Congress” and the zip file iscgd110p020.tar.gz.
>
> So, does anyone know why Alaska does not look right? I need to be  
> able to work with this file as part of an important job assignment.
>
> My second question: How do I add a new field and populate it  
> efficiently? I would like to add the voting results for a bill to  
> the above shape file dataset. There are 1000’s of features in this  
> file, since there are many more land forms than there are districts.  
> So efficiently putting in a “yea” or “nay” in the vote column is  
> going to require a good method.
>
> As you can tell, I am a novice w/ GIS.
>
> Thanks,
>
> Roger
>

On the Options dialog, click on the Rendering tab and then click the  
checkbox next to:
"Make lines appear less jagged...."

This solved it for me.

-gary


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