Archive for the ‘GIS training’ Category

QGIS Sextante Plug-in

Wednesday, August 14th, 2013

In QGIS there are 100’s of plugins available. One of the best I have used is the SEXTANTE plugin. You can download this by going to Plugins>Fetch Python Plugins and search for SEXTANTE.

Once downloaded it should create it’s own menu called Analysis. I just clicked SEXTANTE toolbox and this is what it looks like.

 

Screenshot from 2013-08-14 15:12:34

SEXTANTE can be literally thought of a as toolbox. It has almost everything you need. In the options you can choose to turn on the listed tools.  Some of the options are modeler, the QGIS tools such as interpolation and DEM analysis are included. Tools for LiDAR database management, creating scripts and the list goes on.

Screenshot from 2013-08-14 15:14:31

 

 

SAGA GIS

Thursday, August 8th, 2013

 

SAGA GIS is a stand alone program for processing geospatial data. It can be added to Qgis as a plugin under the Sextant tool bar in the options menu. In order for it to work in Qgis you need to have SAGA installed.  SAGA is available for Windows and Linux users only at this time. The code has been released under FOSS or Free and Open Source Software so if you own a Mac and have experience with coding you can create this program for a Mac.

SAGA was started in 2001 by J. Böhner and O. Conrad and the University of Hamburg.  SAGA stands for System for Automated Geoscientific Analysis. If you want to read more about the history and development you can check out the homepage.

 

 

For the remaining screenshots I will be using Ubuntu 13.04

 

 

 

 

 

 

 

When I open SAGA this is what is looks like. Pretty much a blank page with some menu options at the top and a message bar at the bottom.

 

Screenshot from 2013-08-08 10:13:38

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Customization is fairly easy. Under the window you can choose what windows you wants open.

 

Screenshot from 2013-08-08 10:18:38 Screenshot from 2013-08-08 10:17:33

 

In the screenshots here. I have the windows all open within SAGA and the other I moved them outside. They will stay outside but if you move them too close to the main program they will snap back. The windows open are “Workspace” or the tools available. This is confusing because under the menu bar the same information is called modules. Then the file locations. And then a window that houses the most recent tool run.

 

 

 

 

 

The types of files you can load into SAGA are .CSV, .TXT and .shp files. It will also allow you to create projects.

 

It will allow you to bulk upload as many files as you need and once you do they appear in your workspace under the data window. There is not visual of the data in the main window. You can select thumbnail to see it. When clicking on different .shp files the open files window will update.

Screenshot from 2013-08-08 10:30:48 Screenshot from 2013-08-08 10:34:19

 

In this next graphic I did a lot of things. I used a point layer and ran the module Tin Tool>Shapes to Tin. It created a TIN file. Just to be clear it used triangular irregular network. I double clicked to have the image come up in the main window. You can look at the attribute table, change the color all from the top window. Note: The layers are saved using SAGA’s own extension, but there is the option to convert them if needed.

Screenshot from 2013-08-08 10:46:24

 

 

 

 

 

 

 

 

 

 

 

 

 

SAGA is something that could take forever to know %100 percent. At first glance this is a very powerful stand-alone GIS tool. I say stand-alone because it works great by it’s self. You have more tools in the module that anyone one person is ever going to need. Need a few simulations on the effect of human population, lightning analysis,  and point clouds it has you covered. You have the option to add map layers and even create maps for printing. In Qgis by enabling the SAGA plugin you have some of the functionality. I did noticed a few tools missing. SAGA is not for the light user of any GIS system, it has one purpose and that is to analyze data.

 

A few resources/tutorials on using SAGA.

http://www.saga-gis.org/en/about/references.html

http://live.osgeo.org/en/quickstart/saga_quickstart.html

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Creating a shapefile Layer in Quantum GIS

Monday, April 8th, 2013

In Quantum you can create either a point, line or polygon layer.

Layer>New>Shapefile Layer

Shapefile Layer

Then you can either choose to create a point, line or polygon layer. Before choosing think about the data you are using and what you are creating. If you are working with US Highways and are now creating a layer that just includes highways in Texas you want to choose line for the type of file you create.

For this example Line was chosen as the type of layer.

NewVector

Next choose a CRS or coordinate Reference System. You can either leave it as the default and then change it later (see below) or you can set it when you create the layer.

You’ll notice that the id field is automatically populated. You can delete this field if you don’t want it there. Select id and then click remove attribute.

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To add an attribute:

Under ‘New Attribute” type in the name select the Type  of data the field can hold. You have several options. One is text data this refers to letters or numbers. Then you can choose whole numbers. This refers to numbers such as 100, 300, 500, 10,15,1000. You can not input decimals into this field. Lastly there is decimal number. This includes numbers such as 12.15, 11235,2569843.

You can also choose the width and the precision. Width can be set with all fields. Whole, Text and Decimal. Width refers to the number of characters allowed in the field. This includes punctuation and spaces.  For whole numbers the maximum width is 10. Precision can be set when decimal is highlighted. Precision is the number of places allowed after the decimal. It is entered as zeros in the precision field.

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Once everything is set click on add attribute.

And it will appear in your list below. You can continue like this and add as many field as you like. They can be a mix of text, whole or decimal.

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Once you are done click ok. It is going to ask you to choose a location to save. When you choose a name to save it as it will give it that same name in the attributes table but you can always change that later.

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If the CRS was not set when the layer was created. You can set it now. Right click the layer and then go to set layer CRS.

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Then you can set the CRS.

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Lastly save the layer.

Right click>save as

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You have several options.

Choose the format . It defaults to ESRI shapefile.

Give it a name and choose where you want to save it.

Then you can set the CRS here also.

Layer will leave the CRS as the default. Either WGS if you made no changes when you created it. Or what it was set to when it prompted for the CRS originally. Project will set the CRS to what the project is, if that was set up. Lastly is selected where you can browse and set the CRS to what you want.

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Once your done click ok!

 

Online self paced GIS Training with GIS 101 and 201 coming soon.

Sunday, June 10th, 2012

OK, Folks. We are nearing completion of converting our tried-and-true GIS 101 workshop into an online video driven self paced course. We will have it up and running in June 2012. The idea is to break the 6 hours of course work into about 70 short 5-10 minute modules.  There are two of us knocking out videos and tutorial modules. We want this to go very smoothly, so we are retaining highly acclaimed Litmos as our LMS host (think webhost for online courses) so we don’t reinvent the wheel. That leaves us free to just convert the course and the Litmos framework will take care of logging in learners, administering courses, and issuing digital certifications. GIS Training online

 

Now if there are any folks out there who are really eager to take the course, we are offering the online GIS 101 training($150) at a heavy discount of $50 for only until July 10, 2012. The trade off here, is you need to give us a paragraph of feedback (hey we’re effectively paying you $100)  of what you liked, didn’t like, or didn’t make sense to you.  We maintain our heavy feedback oriented course philosophy, it worked to improve our in class workshop and we want to do it again for our online GIS classes. 

Just call our office at 800 762 3057 and ask for Tami. She will take registration and payment info and we will email you when the course is ready.