It's important when you're first learning your GIS to understand the connections between the theory and the practice. In other words, I can tell you both things like geodatabases, and feature classes, and vector primitives, and points lines, and polygons, and all that stuff, but really it's important to then be able to see well, how is that implemented in the software? How does that work from a practical point of view? So, let's have a look at how that works. Alright. So, what we're going to do here is digitize some existing features to create our own new feature class. I'm first going to create a new file geodatabase, then I'm going to create a new feature class in that, and then I'm going to trace some objects from a satellite image. So, let's see how that goes. Okay. So, I've got a drive here which is my zed drive or Z for my American friends, but wherever you want to store this new data, you just right-click on the folder or the drive and just select new file geodatabase. So, remember this is just a container that you're using to store something, and I like to give it a more meaningful name. So, in this case I'm going to be digitizing some features for an area in Toronto called Queen's Park, so that's what I'm going to name it, you can name it whatever you want. So, now I have a new file geodatabase that's empty. Okay. So, then before I do anything else, I want to add a base map to my empty map document, I'm going to select imagery as my type of base map and just click add. So, what's happening now is that ArcMap is connecting to Ezri servers in the Cloud, it's downloading the image of a map into my map document, just as you would see in the Google Maps or any other kind of map service, but now that's actually being fed into my map document from the Internet. So, we're able to see the entire world, and we'll just zoom in here to the area that I'm interested in mapping, of course could be anywhere, but hey, why not do a little bit of Toronto? So now we can see the great lakes, and this is Toronto here, and you can do the same thing for whatever area it is that you're interested in mapping. You may notice that it does this from time to time as you're zooming in, and the reason is is that every time you zoom in, it has to go and get that new more detailed zoomed in version of the web map from Ezri servers. So, sometimes there's a little bit of lag, sometimes it's pretty responsive, it just depends. If I continue to zoom in here, I'm going to find the area that I'm interested in, so I'm using the zoom tool, and I'm just going to pan over to find, here it is, the area that I'm interested in. So, this is Queen's Park which is the grounds or the area that the Ontario Provincial government is based in, you can see the building there that's the Ontario legislature. All I'm going to do is, they've got this nice oval shaped park around the grounds, and I'm just going to digitize some features from that. Okay. So, what do I mean by digitizing, and what is it we're looking at here, and what does what does this all mean? So, this is a picture of the earth, this is from a satellite image, and this is a raster representation of the world. In other words, these are just pixels that show us what something looks like. I can't select anything off of this, I can't isolate it or work with it as it is right now, what I'm going to do is trace some things into a vector version that I can then work with whatever way I want to use it. So, you'll notice here in my table of contents it's got a base map, I can turn that on and off just like I would any other layer. Now that I have that, I'm going to go back to the file geodatabase that I created, and I'm going to create a feature class. So, I'm going to say new feature class. I have to give it a name, so I'm going to say trees. I have to tell it what kind of future I want, so there's a polygon line point, there's some other ones there that you might get into a bit later, but for now I'm going to represent my trees as points, say next, I'm going to select the coordinate system that I want to use. So, for Toronto that would be Nad 1983 UTM zone 17 N, they may vary depending on where you are and what coordinate system you want to use, that's something we will cover in a different section, but for now that's what I'm going to use, say next. We don't have to worry with the XY tolerance, I'm just going to go with the default for that, and say next again. Now if I want to include my own column or field in my attribute table, I can add it in here, there's two that are added by default, ones called object ID, and one's called shape, those are used internally by the software. You really don't need to pay too much attention to them right now, but for example, if I wanted to include something like type for the type of tree, I can just put in the name of the column that I want to use or the field which is type, and then I have different options here in terms of the type of field I could use, so summer for storing numbers or text or dates. So, for this I want it to be text, and I can just say okay, and I'm going to go with the default there which was 50 characters long, and say finish. Now sometimes you'll get a warning like this where it's saying, "Wait a minute, you just specified a different coordinate system which was UTM zone 17," that's a different coordinate system than the one that's being used to store the imagery that I'm using as my background. For what I'm doing right now, I don't need to worry about that, again that's something we'll cover in this section on coordinate systems and projections and things, I'm just going to say, "Yeah. That's okay. Don't worry about it," and close it. Okay. So, now I have a new feature class in here that is being represented as a dot, I can change that to something more fun. So, let's search for something related to trees. There's a whole lot of different symbols available depending on how specific you want to be, I can have Joshua trees, I love them by the way, Chinese flame trees, but I'm just going to go way down here and pick this one here that I think it's pretty easy to see, and it looks pretty good for what I want to do. So, what I'm going to do now is create my own vector points for those trees. So, I need an editor tool bar to do that, so I go up to customize, toolbars, and there's a whole lot of different tool bars available for various functions or things you want to do, tasks. So, there's one here called editor, I'm going to select that, and now I have an editor tool bar that I can use to do my editing. I'm just going to do some really simple stuff now just so you see how this works, and if you want to create your own future classes quickly, you can do this. I want you to know how to do this from the very beginning. I select the editor drop down here, and say start editing. So, with a database you have to tell it when you want to start editing, and when you want to stop editing, so I've started editing. Then something that may not be obvious if you haven't done this before is there's this little tab way on the Enter button for create features, and if I click on that, it opens a new pane over here on the right saying create features. So, now if I select trees, I can go to my map, and you'll see that it's actually showing a little tree symbol by the curser, I hope you can see that. So, what I'm doing is I'm looking at the trees on the image, I'm saying there's a tree there and if I click there that is now creating a tree symbol or a point in a vector format inside my feature class that represents that tree. So, I can do another one, I could do one for here, and here, I can click all day long and create trees for these locations off of my image. Now, of course it all depends on how much detail there is in the image that you're tracing off of, how accurate you want to be. I'm doing a pretty quick job here, but I'm hoping that you get the idea. So, this gives me a new set of points that I can actually do something with. I can right click on the Create Features parts of trees here and say properties, and see what I've got here. So, I've got trees, points, so I'm setting that up. Okay. I can go to the tab here and say attributes, and so now, when I select an object in my map, so let's say I select this one here, then I can type in the attribute for that particular tree. So, let's say that's a maple tree, I can literally just type in maple, and that now has the maple symbol. I can go to the next one, go to here, so this is a different tree, and maybe this is an oak tree. I can go to a third one, I won't do all of these, I'm just going to show you a couple of them to see how this works. Go to here and maybe this is a peach tree. Okay. You can continue to do this as much as you need to, and then I can say stop editing. When I say stop editing it will ask me, "Well wait a minute don't you want to save your edits?" It doesn't save them automatically. So, you have to make sure to do this, and I'm going to say, "Yes please do save those." So now, if I open the attribute table, you can see that the attributes that I typed in maple, oak, and beach are actually associated with those points in my digitized versions. So now, I can select that, and see that particular point on the map, I can do the same thing for oak and so on. That's all there is to it, that's literally how you can create your own data, you can easily create your own file geodatabase, you can easily create your own feature classes, and they can either be points lines or polygons, and it's really that straightforward.
