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Recursos de SIG y Geomatica para Latinoamerica (GIS & Geomatics for Latin America)

21 Feb

Hola!
Esta vez les escribo para compartirles un excelente sitio de recursos de Geomatica y SIG Libre que puede ser especialmente util para quienes trabajan en Mexico y otras partes de America. Espero que hayan tenido un buen fin de semana y pronto les platicare sobre cuestiones tecnicas respecto a la combinacion de analisis de visibilidad y movimiento 😀

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Sound Mapping & Map Projection manual

18 Feb

Hey guys!

I hope you had a good week.

This is just a quick note to share this article about how different projects are mapping a diversity of sounds in many parts of the world. I think this is a great idea and one of the theoretical discussions I enjoy the most is precisely how we can integrate intangible variables into computer models within archaeology. I suspect this kind of material will probably become a very important source of information in the future.

About other things, today I also found a very nice (and free) manual about map projections from the USGS.

Have a great weekend 😀

 

In need of GIS data? Try this great site :D

15 Feb

Hello guys, just a quick note to tell you about a really good site to obtain GIS data from all around the world.

Vectorial and raster data is available.

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!

How to batch merge multiple shapefiles

11 Feb

Hey guys, in one of my last posts I shared a very useful tool to split a shp into several by attribute.  I found another great script by Gerry Gabrisch but this time to merge multiple shapefiles. There are several ways to do this and if you are not that familiar establishing the arguments or parameters in a Phyton script you will probably prefer this other utility.

Tlaloc bless the internet! 😀

Have a great weekend!

Converting a single shapefile into several (Split by attribute)

8 Feb

Hello again!

Just a quick note to tell you that today I found a very useful tool set to split a layer or shapefile in many shapefiles based in an attribute from the table.

This is a very quick way to separate a layer of roads, counties and so on. It was created by the USGS and have also another 3 additional tools.

I hope is as useful for you as it was for me 🙂

GIS Tool

 

 

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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