newbie questions

6 messages · tom sgouros, Alex Mandel, Dan Putler

Original

1

6

Dan Putler

Sun, Nov 15, 2009 7:40 PM #

Tom,

Er, what exactly is your data? Do you have data that is linked to zip
codes and you want to do a "thematic" (choropleth) map of the data? Do
you have point data (say a lat/lon values), and want to plot the points?
Given what you've said, hard to figure out how to get you going in the
right direction.

Dan

On Sun, 2009-11-15 at 22:30 -0500, tom sgouros wrote:

Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

Hi Tom!

I'm a geographer and R enthusiast too, but what I can say is: R is a great
software to statistics. The final production of maps, although it's
possible, it's simple and faster made with GIS softwares, like GRASS,
Quantum GIS or ArcGIS.

This is exactly my quandary.  I have some data I want to map, and I have
no idea how to do it and none of the introductions I've found speak to
what I thought was a pretty simple task.

I first thought maybe I should use a GIS, since it's geographic data,
but all the GIS documentation I can find is about how to analyze data
that's already available.  There are no end of Grass examples using this
North Carolina dataset that comes with the installation, but I don't
live in North Carolina and I don't want to analyze their data.  I want
to analyze mine, but I can't figure out how to get it in, and that's
what I'm using R for.

If you are telling me there is a simpler way to do this, I am all ears
(eyes), especially if it uses grass or qgis which I can afford, and not
Arc, which I can't.

Queries of GIS guys told me that what I need to do is to get my data
into a shape file first and then a GIS can help me display it, so I
turned to R for that.  Was I wrong there, too?

Most of the data I want to map is not currently in any format at all.
It's just numbers I have.  I have shape files for the geography and I
want to apply my numbers to those shapes and draw maps in color, and I
also would very much like to draw the 3d kind where the geographic area
is raised up according to some value.  (I don't know if there's a name
for this.)  I tried to use a spreadsheet to get my data attached to the
shapes, but as soon as I realized I needed to do a join of my data and
the shape file data I began to look for alternatives.

I know that I'm working at a very low level here, but in addition to
Roger's advice before about how to get R to cooperate, I would be
grateful for any advice such as you've provided about what exactly R is
good for in my task and what a GIS is good for.  Your note advances me
down the field quite a bit, but if there's more, I'd be interested to
know it.

Many thanks,

 -tom

My tip is: organize data with spreadsheet and GIS softwares, import (as
shapefile, if possible) in R and make your statistical analysis and
statistical columns of data, export to another shapefile and manipulate the
final map in GIS softwares.

I repeat, it's possible make all these steps in R, and generate great maps,
but the most simple way is above. Personally, I use R to make the final maps
only when I have to produce a long series of simple maps.

I think the best way is the integration of GIS software with R, each one
with his specialty.


King regards,

Raphael Saldanha
BRAZIL
saldanha.plangeo at gmail.com

	[[alternative HTML version deleted]]

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R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
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Dan Putler
Sauder School of Business
University of British Columbia

tom sgouros

Sun, Nov 15, 2009 8:18 PM #

Dan Putler <dan.putler at sauder.ubc.ca> wrote:

The data is mostly from past elections, so it's vote totals or
demographic data within some district.

Google tells me that choropleth is the name of precisely the kind of
thing I'm trying to make, thank you for expanding my vocabulary today.

Is there a name for the bar graph kind of thing?  (Here's an example:
http://www.turbosquid.com/FullPreview/Index.cfm/ID/346428 )

Thank you,

 -tom

On Sun, 2009-11-15 at 22:30 -0500, tom sgouros wrote:

Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

Hi Tom!

I'm a geographer and R enthusiast too, but what I can say is: R is a great
software to statistics. The final production of maps, although it's
possible, it's simple and faster made with GIS softwares, like GRASS,
Quantum GIS or ArcGIS.

This is exactly my quandary.  I have some data I want to map, and I have
no idea how to do it and none of the introductions I've found speak to
what I thought was a pretty simple task.

I first thought maybe I should use a GIS, since it's geographic data,
but all the GIS documentation I can find is about how to analyze data
that's already available.  There are no end of Grass examples using this
North Carolina dataset that comes with the installation, but I don't
live in North Carolina and I don't want to analyze their data.  I want
to analyze mine, but I can't figure out how to get it in, and that's
what I'm using R for.

If you are telling me there is a simpler way to do this, I am all ears
(eyes), especially if it uses grass or qgis which I can afford, and not
Arc, which I can't.

Queries of GIS guys told me that what I need to do is to get my data
into a shape file first and then a GIS can help me display it, so I
turned to R for that.  Was I wrong there, too?

Most of the data I want to map is not currently in any format at all.
It's just numbers I have.  I have shape files for the geography and I
want to apply my numbers to those shapes and draw maps in color, and I
also would very much like to draw the 3d kind where the geographic area
is raised up according to some value.  (I don't know if there's a name
for this.)  I tried to use a spreadsheet to get my data attached to the
shapes, but as soon as I realized I needed to do a join of my data and
the shape file data I began to look for alternatives.

I know that I'm working at a very low level here, but in addition to
Roger's advice before about how to get R to cooperate, I would be
grateful for any advice such as you've provided about what exactly R is
good for in my task and what a GIS is good for.  Your note advances me
down the field quite a bit, but if there's more, I'd be interested to
know it.

Many thanks,

 -tom

My tip is: organize data with spreadsheet and GIS softwares, import (as
shapefile, if possible) in R and make your statistical analysis and
statistical columns of data, export to another shapefile and manipulate the
final map in GIS softwares.

I repeat, it's possible make all these steps in R, and generate great maps,
but the most simple way is above. Personally, I use R to make the final maps
only when I have to produce a long series of simple maps.

I think the best way is the integration of GIS software with R, each one
with his specialty.


King regards,

Raphael Saldanha
BRAZIL
saldanha.plangeo at gmail.com

	[[alternative HTML version deleted]]

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R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

--------------------------------------------------------
 Check out "Ten Things You Don't Know About Rhode Island"
     http://whatcheer.net      http://sgouros.com

tom sgouros

Sun, Nov 15, 2009 8:27 PM #

tom sgouros <tomfool at as220.org> wrote:

I should have also said that I have both SHP files and E00 files to
describe the boundaries of the districts, but have no feeling about
which I should prefer or why and I wonder if anyone else does.  The SHP
files come with an XML description that seems not to be used by grass.
The E00 files maybe come with a description of their own projection,
while I had to identify a projection to specify it to grass, but
otherwise I don't know why one would be better or worse.

Thanks,

 -tom

Google tells me that choropleth is the name of precisely the kind of
thing I'm trying to make, thank you for expanding my vocabulary today.

Is there a name for the bar graph kind of thing?  (Here's an example:
http://www.turbosquid.com/FullPreview/Index.cfm/ID/346428 )

Thank you,

 -tom

On Sun, 2009-11-15 at 22:30 -0500, tom sgouros wrote:

Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

Hi Tom!

I'm a geographer and R enthusiast too, but what I can say is: R is a great
software to statistics. The final production of maps, although it's
possible, it's simple and faster made with GIS softwares, like GRASS,
Quantum GIS or ArcGIS.

This is exactly my quandary.  I have some data I want to map, and I have
no idea how to do it and none of the introductions I've found speak to
what I thought was a pretty simple task.

I first thought maybe I should use a GIS, since it's geographic data,
but all the GIS documentation I can find is about how to analyze data
that's already available.  There are no end of Grass examples using this
North Carolina dataset that comes with the installation, but I don't
live in North Carolina and I don't want to analyze their data.  I want
to analyze mine, but I can't figure out how to get it in, and that's
what I'm using R for.

If you are telling me there is a simpler way to do this, I am all ears
(eyes), especially if it uses grass or qgis which I can afford, and not
Arc, which I can't.

Queries of GIS guys told me that what I need to do is to get my data
into a shape file first and then a GIS can help me display it, so I
turned to R for that.  Was I wrong there, too?

Most of the data I want to map is not currently in any format at all.
It's just numbers I have.  I have shape files for the geography and I
want to apply my numbers to those shapes and draw maps in color, and I
also would very much like to draw the 3d kind where the geographic area
is raised up according to some value.  (I don't know if there's a name
for this.)  I tried to use a spreadsheet to get my data attached to the
shapes, but as soon as I realized I needed to do a join of my data and
the shape file data I began to look for alternatives.

I know that I'm working at a very low level here, but in addition to
Roger's advice before about how to get R to cooperate, I would be
grateful for any advice such as you've provided about what exactly R is
good for in my task and what a GIS is good for.  Your note advances me
down the field quite a bit, but if there's more, I'd be interested to
know it.

Many thanks,

 -tom

My tip is: organize data with spreadsheet and GIS softwares, import (as
shapefile, if possible) in R and make your statistical analysis and
statistical columns of data, export to another shapefile and manipulate the
final map in GIS softwares.

I repeat, it's possible make all these steps in R, and generate great maps,
but the most simple way is above. Personally, I use R to make the final maps
only when I have to produce a long series of simple maps.

I think the best way is the integration of GIS software with R, each one
with his specialty.


King regards,

Raphael Saldanha
BRAZIL
saldanha.plangeo at gmail.com

	[[alternative HTML version deleted]]

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

--------------------------------------------------------
 Check out "Ten Things You Don't Know About Rhode Island"
     http://whatcheer.net      http://sgouros.com

Alex Mandel

Sun, Nov 15, 2009 8:29 PM #

tom sgouros wrote:

It sounds like what you need is a base map of districts from whatever
governmental agency has jurisdiction(Fed, State or County). It will
likely come as a shapefile or other similar format as polygons. You will
then Join your election data to this spatial data set based on some sort
of shared ID key that exists in both.

This could be done easily in either QGIS or R. I would leave GRASS out
of the discussion for now if we're just talking about making a map and
bring it back in if you start wanting to analyze the spatial
relationship between your data and other data sets.

FYI, there are both R and GRASS plugins for QGIS which I think is a good
tool for getting started with GIS.

Most people would call that link you sent a 3D visualization, there are
lots of ways to do that in GRASS(nviz), R and even Google Earth (fairly
common).

Alex

Dan Putler

Sun, Nov 15, 2009 8:32 PM #

I'd go with the shapefiles, the E00 files are ArcInfo export format
files, and it is very likely you would convert to shapefile sets along
the way.

Dan

On Sun, 2009-11-15 at 23:27 -0500, tom sgouros wrote:

tom sgouros <tomfool at as220.org> wrote:

Dan Putler <dan.putler at sauder.ubc.ca> wrote:

Er, what exactly is your data? Do you have data that is linked to zip
codes and you want to do a "thematic" (choropleth) map of the data? Do
you have point data (say a lat/lon values), and want to plot the points?
Given what you've said, hard to figure out how to get you going in the
right direction.

The data is mostly from past elections, so it's vote totals or
demographic data within some district.

I should have also said that I have both SHP files and E00 files to
describe the boundaries of the districts, but have no feeling about
which I should prefer or why and I wonder if anyone else does.  The SHP
files come with an XML description that seems not to be used by grass.
The E00 files maybe come with a description of their own projection,
while I had to identify a projection to specify it to grass, but
otherwise I don't know why one would be better or worse.

Thanks,

 -tom

Google tells me that choropleth is the name of precisely the kind of
thing I'm trying to make, thank you for expanding my vocabulary today.

Is there a name for the bar graph kind of thing?  (Here's an example:
http://www.turbosquid.com/FullPreview/Index.cfm/ID/346428 )

Thank you,

 -tom

On Sun, 2009-11-15 at 22:30 -0500, tom sgouros wrote:

Raphael Saldanha <saldanha.plangeo at gmail.com> wrote:

Hi Tom!

I'm a geographer and R enthusiast too, but what I can say is: R is a great
software to statistics. The final production of maps, although it's
possible, it's simple and faster made with GIS softwares, like GRASS,
Quantum GIS or ArcGIS.

This is exactly my quandary.  I have some data I want to map, and I have
no idea how to do it and none of the introductions I've found speak to
what I thought was a pretty simple task.

I first thought maybe I should use a GIS, since it's geographic data,
but all the GIS documentation I can find is about how to analyze data
that's already available.  There are no end of Grass examples using this
North Carolina dataset that comes with the installation, but I don't
live in North Carolina and I don't want to analyze their data.  I want
to analyze mine, but I can't figure out how to get it in, and that's
what I'm using R for.

If you are telling me there is a simpler way to do this, I am all ears
(eyes), especially if it uses grass or qgis which I can afford, and not
Arc, which I can't.

Queries of GIS guys told me that what I need to do is to get my data
into a shape file first and then a GIS can help me display it, so I
turned to R for that.  Was I wrong there, too?

Most of the data I want to map is not currently in any format at all.
It's just numbers I have.  I have shape files for the geography and I
want to apply my numbers to those shapes and draw maps in color, and I
also would very much like to draw the 3d kind where the geographic area
is raised up according to some value.  (I don't know if there's a name
for this.)  I tried to use a spreadsheet to get my data attached to the
shapes, but as soon as I realized I needed to do a join of my data and
the shape file data I began to look for alternatives.

I know that I'm working at a very low level here, but in addition to
Roger's advice before about how to get R to cooperate, I would be
grateful for any advice such as you've provided about what exactly R is
good for in my task and what a GIS is good for.  Your note advances me
down the field quite a bit, but if there's more, I'd be interested to
know it.

Many thanks,

 -tom

My tip is: organize data with spreadsheet and GIS softwares, import (as
shapefile, if possible) in R and make your statistical analysis and
statistical columns of data, export to another shapefile and manipulate the
final map in GIS softwares.

I repeat, it's possible make all these steps in R, and generate great maps,
but the most simple way is above. Personally, I use R to make the final maps
only when I have to produce a long series of simple maps.

I think the best way is the integration of GIS software with R, each one
with his specialty.


King regards,

Raphael Saldanha
BRAZIL
saldanha.plangeo at gmail.com

	[[alternative HTML version deleted]]

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

_______________________________________________
R-sig-Geo mailing list
R-sig-Geo at stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo

Dan Putler
Sauder School of Business
University of British Columbia

Alex Mandel

Sun, Nov 15, 2009 8:34 PM #

tom sgouros wrote:

For your purposes the shp will be easier to work with, the E00 file
contains the same information and something called Topology which is
irrelevant to this particular use. The XML file is metadata, none of the
software involved here directly uses it, the projection information is
stored in the .prj file for shapefiles.
SHP is more widely recognized by software and in most cases E00 just
gets converted to it at some point anyways.

Alex