Lab 1 - Part 2

Creating a Map in ArcGIS

Digitizing, Text, & Symbology

After you have created your shapefiles and you begin digitizing, you may not see your shapefile in the Create Feature window. You may need to go back and create a New Template. In the Create Features box, go up to the top menu and click on the second icon (Organize Templates). That will take you to the Organize Feature Templates window and you should be able to check the box next to the shapefile you want to work with. It will then appear in the Create Features window and you are set to begin digitizing.

Unlike CAD drawings, the features you are creating will not snap to the base map that you are using as a backdrop. You start a segment by placing the first vertice (vertex) and right clicking with the mouse. You can add as many vertices in between as you like, but if you have a straight line, you may only need 3 - 5. When you add the last one, to close the segment you either double click (right click), or left click on the mouse and in the drop down menu, you can click on Finish sketch. You also have an option called Finish part and this is useful when you are digitizing many segments that are related to each other and will have the same attributes, but do not form one cohesive feature. For example, you might have a road that crosses a river and you want the segments, though they will be interrupted by a water feature, to be related. If you select Finish Part, you can digitize to the river, click Finish Part and then start up again on the other side and continue digitizing and when you click them on and off, all parts will appear and disappear. This drop down menu will give you many other options as well. The dropdown menu under Editor also has many useful options for digitizing. Snapping allows you to set what you want to be snapped to i.e.: edge, vertex, and endpoint. Options, sets the snapping tolerance. Experiment with this and see how if you set the snapping tolerance from a default of 7 to 30 you can actually see the vertex moving from where you place the cursor to the closest vertex that is active. If you chose edge, that will snap the point to almost anything, so you must be careful how the parameters are set. The tolerance can be set using pixels or map units. Experiment using various options. For example, the option Streaming will allow you to add many vertices without having to click, you just move your cursor and the vertices are placed. You can also use the sketch tools for anything that is not a straight line.

SYMBOLOGY

For this part of the assignment, we will change the parameters of the features you have already digitized through the layer (shapefile) properties. 

1. First, make the major roads red with a line width of 3 pt. and the secondary roads black with a line width of 1 pt. The roads are outlined in the first part of this assignment. You can do this by double clicking on the layer name or by right clicking on the layer (shapefile) name and this will bring up a drop-down menu and at the bottom you will see Properties. Click on Properties and it this will bring up Layer Properties box. Click on the Symbology tab - this brings up a window that allows you to select the color and fill for the polygon or the color and width of the line if you are symbolizing a “polyline” shapefile. You can also get to a window that will allow you to make these changes by double clicking the colored box next to the shapefile (layer) name. This will bring up a window called the symbol selector; here you can change the feature style and color.

ATTRIBUTE TABLE

The Attribute Table of a shapefile is where all of the related data is stored. You may create a shapefile and use it in many projects. Over a short period of time, the attribute table may expand to contain many fields of information regarding the feature you are representing with that shapefile or layer. This is what a populated Attribute Table looks like – the rows are referred to as “Records” and the columns are the “Fields”.

When you add a new field for the road name (described below) you will be adding your first field to the Attribute Table of the shapefile you created, there are two fields by default and these are the FID and shape. So in the Attribute Table above, you see 20 records visible and 7 fields of information pertinent to your shapefile. The PCODE, Shape_length, and Shape_area are all Integer type of data and the Potential is a field with Text data type. When you add the Road name, you have to select Text for the data type. The shape is all Polygon, referring to area, which is why you are able to calculate area in the Shape_area Field and the FID is the number of polygons that were created. You can add as many fields of information as you like and this data will always be related or attached to the shapefile. If you click on a polygon in the Data View window, with the small in the blue window on the tools toolbar, that is the Identify tool and that will bring up the attribute data about that particular feature within the shapefile.

TEXT

Text or labels can be added two ways, by adding it to the Attribute Table and by using the Text tool Capital A in the Drawing Tool set, (if not activated it can be found by going up to Customize (top menu) then click on Toolbars and then Draw. It is important to understand the difference. If you add the text using the Attribute Table, it will be directly related to a layer or shapefile. You can check or un-check the labels in a shapefile and make general rules for all of the text in that shapefile related to placement, font, color, etc. No matter what project you are using the shapefile in, the text will always be available. However, if you want to draw attention to a certain area, then you would want to use the Text tool and not have it associated with the shapefile (layer) in the Attribute Table. If you add text or labels using the Text tool, it will only appear within your map document (mxd). Say you add a label across the Urbanized area of Salt Lake City in this lab, you can un-check all of the layers and the only thing that will be visible in the window is the text Salt Lake City.

Below what you are seeing is text within an Attribute table (road names) and text using the Text tool Salt Lake Urbanized Area. If you remove the shapefile, the text input with the Text tool is the only thing left and will remain so until it is deleted. That is the only way to remove it from the window.

Add text to all of the roads. Before you specify the labeling properties, you must add a field that you will call Road Name or just Name. (If you call it Road Name, be sure to use an underscore (_) between the words as ArcGIS does not recognize spaces in most toolboxes). You do this by right-clicking on the shapefile name and go to Open Attribute Table. Click the icon in the top left called Table Options, you will see the option to add field (6^th choice from the top) (you must be out of the edit mode to do this, meaning that if you went to Editor and clicked on Start Editing, you must go back to Editor and click on Stop Editing).

Type in the field name. Depending on what kind of data you want to add to the table, you can specify in the Type box. Look at the dropdown menu to see your selections. In this case you want to choose Text for the name. Then, keeping this attribute window open and using your identify tool, the with in the circle, place it over each road segment and you will see in the identify window, which polyline it is. This will be the FID #, or field ID #. Find this number in your attribute table. To add data to the new Field, you must be in the Edit Mode, so now go back to Editor and click on Start Editing, (don't forget to make sure the shapefile is highlighted again in the Create Features window). Now you will be able to add your road name in the Road Name field.

Once you have added Text to the Attribute Table, you can change the color and font by clicking on the Label tab in the shapefile (layer) Properties box, here you can specify font, color, size, and placement. I don’t usually do much with placement unless I am working with point data; the only thing you need to remember with text placement is consistency (see the Cartographic Principals write-up on www5). Make sure the labels are all on the same side of the feature (in this case -roads). When you use the labels from the Attribute Table, you right click on the shapefile and then in the drop-down menu, go down to Label Features. This will add all of the labels in the Attribute Table. They are all treated the same, so if you change something in the Labels tab in the Properties Box, it will change for all of the labels. Click on the Labels tab in the Layer Properties Box as below:

A very important consideration in adding text to linear features is that you do not want the text to cover any feature or be so close to a line that it makes the text illegible. There are two ways to deal with this problem and I will let you decide how you want to deal with it, because you will no doubt run into this with the roads. Please check on the www5 website the Cartographic Tips, as I outline what makes a good map and what mistakes to avoid. The two alternatives are:

1. Add a halo behind the text – this puts a white background behind all of the text in that field of the shapefile’s attribute table (in this case Road_Name or Name) and if it crosses a feature, it will still be easy to read. You do this by clicking on Symbol in the Labels tab (see above) that takes you to the Symbol Selector Window and

Click on Edit Symbol – this takes you to the Editor Window and click on Mask in the middle. This brings up the window that allows the user to click on Halo. The size of the halo is 2 by default and on the left it shows you what the text will look like.

2. You can also Convert Labels to Annotation so you can move them and treat each one individually. In the drop-down menu below Label Features, you will see Convert Labels to Annotation. Click on Label Features first, then Convert Labels to Annotation.

The reason you want to do this, is that all labels that are part of the attribute table are treated the same and you can set placement properties, font size, type and color by clicking on the Labels tab in the Properties Box for each shapefile, but in the event that you need to move text, then at the last minute, before you put the final touches on your map, you can go back and Convert Labels to Annotation and single click on any of the labels and the select box (turquoise dotted line) will appear around it, double click and the Properties Box appears and you are able to change the font and color just for that piece of Text. If you single click on it, the turquoise dotted line appears and if you use the solid black arrow (select elements tool in the Tools toolbar) you can move the text.

Now you can move it. If you double click on this piece of text, you can change the font type, color and size and it will only affect that piece of selected text. It is important to wait until you have your final map put together in Layout View before you do this however, because there are many tasks that will throw your labels off and they may not look correct.

Now that you have your roads and buildings named and in the appropriate color, we will finish this map and make the layout.