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http://spatialtech-humanities.com/

11 Aug

I recently migrated all the content from this blog to my new website!

www.spatialtech-humanities.com, I’m looking forward to see you there.

Hi all,

I hope you are having a great summer! Just a quick note to say that I’m migrating my blog to my new website. I hope you like it and continue following my research. Don’t hesitate to contact me anytime 🙂

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Second Call for Papers Computer Applications in Archaeology 2012

26 Nov

CAA Southampton

CAA2012 Call for Papers

Submissions are requested for the 2012 Computer Applications and Quantitative Methods in Archaeology to be hosted by the Archaeological Computing Research Group in the Faculty of Humanities at the University of Southampton.http://www.caa2012.org

The main aim of the CAA conference is to bring together researchers, professionals and students with an interest in the field of computer applications and quantitative methods in archaeology. We therefore welcome submission of abstracts in English of up to 500 words that:

–              Describe original, technically excellent, critical, and/or synthetic research

–              Focus on interesting computation and/ or quantitative methods and theories applied in archaeology and related disciplines

You may choose to present your research via a long paper (20 minutes plus 10 minutes for questions and handover), short paper (10 minutes plus 5 minutes for questions and handover), or a poster. You may submit your research to a specific proposed session or to the general session. Poster sessions will run on each day of the conference and posters will be linked in the conference documents and website to the sessions to which they were submitted. Please indicate your preference in your submission.

Provisionally the conference will be divided into six themes:

1.            Data Analysis, Modelling, Management, Integration and Visualisation

2.            Field and Lab Recording

3.            Geospatial technologies

4.            Human Computer Interaction, Multimedia and Museums

5.            Simulating the Past

6.            Theoretical Approaches and Context of Archaeological Computation

The list of proposed sessions is available online:

http://www.southampton.ac.uk/caa2012/submissions/CAA2012_proposed_sessions.pdf

You should submit your paper via the CAA2012 Open Conference System available online:

https://www.ocs.soton.ac.uk/index.php/CAA/2012/schedConf/cfp

The deadline is 11:59pm 30 November 2011. Accepted papers will be announced and conference booking system will open on 21st December 2011. Please note that at least one of the authors of a paper or poster must be registered for and attend the conference.

All research presented at CAA2012 may be submitted after the conference for peer review for publication in the conference proceedings. These will be published prior to CAA2013.

Note: If you would like your paper to be considered for the CAA Recycle Award then please indicate this in your submission:

http://www.southampton.ac.uk/caa2012/award/index.html

Look also for our session about the study of movement:

Loc(i) Motion: Current technologies and computational methodologies for exploring human movement in the past and present

Online tool to convert .kml to .shp

1 Aug

Hi guys, today I just wanted to share with you a very useful tool that I found.

Is called Kml2Shp and it exports online any kml to ESRI shapefile format or the other way around. Very nice tool 🙂

http://www.zonums.com/online/kml2shp.php

Script to sum values from one field and place them into another field ARCGIS

31 May

Hi guys,

Today I had to sum the values from a field from a raster file and write the output into another. Despite you’ll think that Arcgis would have a tool to do this in a simple way, I found out that this was not necessarily the case :p

I wrote an script in python to solve this. I hope you find it useful.

What the script does is to sum the values from a field writing the result into another field in the table.

You can copy this and add it into your toolbox 🙂

The arguments that are necessary are:

#(1) table = table containing the field you want to sum

#(2) fieldtosum= the field that you are going to sum

#(3) fieldwrite= the field in which the sum is going to be writen

#Script
import arcgisscripting, sys
gp = arcgisscripting.create()
table = sys.argv[1]
fieldtosum = sys.argv[2]
fieldwrite = sys.argv[3]

rows = gp.SearchCursor(table)
row = rows.Next()
p = 0.0
while row:
p += row.getvalue(fieldtosum)
print p
row = rows.next()
#calculate field
gp.calculatefield(table,sys.argv[3],float(p),”PYTHON”)
#End——-

Very soon I’ll be writing about how to do a series of variants of visibility analysis such as “Directional Viewsheds” and “Higuchi Viewsheds” that can be very useful in archaeology 🙂

The importance of the correct use of projections in GIS data

21 Mar

Hello guys,

Today I was explaining somebody about the consequences of messing up the geographic coordinate systems and projection when you are working with GIS data.

In reality once you decided which projection you are going to work with, to have all your data with the same projection or to transform data that is in another projection is very simple. However, the problem comes when you mix data with different projections such as, for instance, a DEM with one CS and a shapefile with another. Although software like Arcgis warns you when you are working with data in two different systems, it doesn’t stop you from doing spatial analysis or any other kind of work. To illustrate this problem (that can be quite serious if you get it wrong), I’m going to show you the difference using two point shapefiles with THE SAME DATA but DIFFERENT PROJECTION.

The red dots represent archaeological sites that were recorded in ED_1950_UTM_Zone_30N and the black dots are the same sites but projected as WGS_1984_UTM_Zone_30N

Different projections

Although the difference may not seem large (182.923 m), in fact, when performing spatial analysis this will have its impact in the results. I know that in archaeological cases this might not be an error that cause a major disaster like calculating wrong, for instance, flooding levels of a damn. However, it is highly important that you get it right in order to have correct results.

There is a very useful resource where you can find the main geographic_transformations_complete, parameters and areas of use released by ESRI that can be used with all “project” tools in Arcgis.

Ok, I hope this is useful and see you soon 🙂

Workaround for Arcgis batch models (or what to do when batching a model just fails)

14 Feb

Ok, so many of you are probably already aware that when you create a model in Arcgis in order to batch it you need to make the variables lists. However, there are sometimes that this just fails and it not allows you to batch your model. I encountered this problem working with a quite complicated model and looking for different solutions I figured out this one. You can just create a script instead of a model, but if you don’t have time or you are not a super scripting nerd 😀 there is another way to make it work. Is actually quite similar to the way you do macros in IDRISI.

For the sake of explanation here Im going to put as example a simple process (create a buffer):

Let’s say you create your model and you want to batch process it.

1.Open the command line either in Arcmap or Arccatalog. To make sure that your model works well before you create your workflow in Excel, enter the parameters of your model in the command line and run it.

2. Once you are sure it is working properly, copy the parameters to a worksheet in excel.

(If you are using arccatalog you can set the absolute paths to your layers, but if you added all the information into an arcmap project the model will take the relative paths so in the parameters you can just input the name of the file rather than the whole path)

3. Once in excel you can just drag down the values filling up the parameters, modifying the names of the files you want to run in subsequent models.

4. Delete all the other sheets in the book (Sheet1,2 and so on TAB/right click/delete). Save as .cvs (Comma delimited).

(This will allow you to modify in the next step the file and save it directly to .txt)

5. Open it your word processor, click Find and Replace. Replace “,” for one space.

6. Save the document as .TXT

7. Open it in Notepad.

8. Copy and paste all in the command line and run it! (you are ready to go for a nice coffee while the machine works for you :D)

You can do the same with more complex models, just add the parameters that are necessary in your model.

Have a great day!

Changing the symbols of an entire layer in ARCGIS

1 Feb

Hello!
As always, there are small things that make our life easier when we are working with Arcgis. But sometimes, they are so obvious and -small-, that we tend to forget how to do them :p

This time, a friend had a layer with many roads and he asked me how to do all of them thicker. To change them all at the same time you just go to:

Layer properties/Symbology/Symbol Tab (above the lines representing each of the roads in this case)
Left click/ Properties for all symbols

There you can change the properties of all your features at the same time 🙂

Happy modelling…

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