Introduction to GIS and Census Mapping: Part II
by Frank Donnelly, Geospatial Data Librarian, CUNY Baruch College. Version 1.12
Making Maps in the Layout View of ArcGIS
Exploring the Layout View
In Part I, you were introduced to the ArcMap interface and learned how to work with layers and tables in the Data View. In Part II, we will focus on how to create a finished map using the Layout View. The Data View is generally used for importing, processing, symbolizing, exploring, and analyzing your data. Once you are ready to create a finished map, you move on to the Layout View.
In the lower left-hand corner of the Data View window are a series of three small buttons. The first button is a globe, which toggles you to the Data View (which you are currently in). The second button is a piece of paper. Press this button now to toggle to the Layout View, as seen in Figure 1.
The default for the layout view mimics the look of a standard 8 1/2 by 11 piece of paper with a portrait orientation. But since a map of the continental US is more suited to a landscape orientation, let's adjust the page. Go to File > Page Setup and select Landscape in the Page and Print Setup Window, and click OK.
This adjusts the page accordingly.
But something doesn't look quite right. In the Layout View, ArcMap will show the image that is currently being displayed in the Data View inside a window. While we have adjusted the page, we haven't adjusted the window to fit within the page.
Do a single left click on the data window. This will high-light it in blue. Click on it again, hold the left mouse button down, and drag the window to the center of the page. Then, release the button, click on one of the corners of the window (there should be a blue box in each corner) and drag it from the box to reduce the size of the window. Repeat each operation until you get the data window within the confines of the page. Be sure to leave some gap between the border of the window and the edge of the page.
Once the page is centered, we may have to adjust the actual geography that appears in the window so that it is centered. Use the Zoom Out tool, and click it in the middle of the window to zoom out, so you can see the entire continental US (Figure 4).
Then select the Zoom In tool, draw a box around the continental US, and you will zoom in so that it fits within the screen. Use the hand tool to drag the image around to center it (if necessary).
So, all of the Data View tools will work within the Layout View. You can use them to adjust your layers so that they fit within the confines of the page. One of the most confusing aspects of the Layout View is that it also has its OWN toolbar, which you can use to zoom in and out and move the page around - but with different results.
Find the Layout toolbar. The first two buttons on the toolbar are magnifying tools for zooming in and out - they both have magnifying glasses in front of a piece of paper. If you don't see the toolbar, check to make sure you have it turned on by going to View > Toolbars > Layout Toolbar. Click on the Layout Zoom Out button, hover your mouse over the center of the map, and click to zoom out a few times, and observe what happens.
Compare Figure 5 to Figure 4. See the difference? We haven't zoomed out to see more geography. Rather, we have zoomed out to see more of the page. The Data View zooms are used to alter the extent of your geography, or the scale of your map. The Layout View zooms are used to alter your view of the page. It's like holding a piece of paper close to your face or holding it further away. Use the layout tools to zoom out to see how all of your elements are composed on a page. Use the layout tools to zoom in in order to do detailed work on a small corner of the page, like adding some text notes or editing a legend. The Layout toolbar also has tools for dragging the page around, and zooming to the full extent or to a fixed width.
! One of the most common mistakes is to mix up the Data View and Layout View toolbars by inadvertently selecting the wrong zoom button. If you make a mistake, don't panic. Remember that each toolbar has a back button that lets you go back to your previous extent. Alternatively, you can use the Windows shortcut CTRL Z to undo a previous operation (and CTRL Y to redo an operation).
Return to the full extent page view by using the Layout Toolbar. Hit the button that has 1:1 written on a small page.
Adding Titles and Legends
Let's spice up our map a little by adding a title. Go up to Insert on the top menu and select Title. A little cursor will appear somewhere on the screen with the word Text written inside. Erase this text and write a meaningful title like "Out of State Migration in Large Metro Areas" and hit enter. Then do a single left click on the title to hi-light it, and drag it around the page to center it.
!Did you accidentally select and drag the whole page instead? Another common mistake made in the layout view is selecting the wrong object. Remember to CTRL Z to undo what you did. Just try to click right on the object until it's outlined in blue - that means that you have that object selected. If you don't want anything selected, click in the area outside the page. This essentially selects nothing, and you'll be clear to try again.
While we are able to see our data classification scheme and categories in the Table of Contents in the Data View, this information is not going to automatically appear in our map. We have to add it manually by creating a legend. Go up to Insert and select Legend.
We will have five windows to step through to set up our legend. In the first window, we're asked which features we would like to add to our legend. The window on the left shows what features are in our map, and the window on the right shows what will be added to the legend. You can change the order of items that appear in the legend using the bold up and down arrows to the right. By default, all the features are added. We certainly want metros_2003 to appear, as we need to communicate what these areas are and what values are being shown. On the other hand, the states_2000 layer is being used as a simple reference layer. It's rather obvious that we're looking at an outline of the US, so it isn't necessary to list this feature in the legend.
Select the states_2000 layer in the legends item window and select the single, left, pointing arrow to move this layer out of the legend box. Then click Next.
On the 2nd legend screen, depicted in Figure 8, we can change the appearance of the title of our legend. In this case, let's delete the word Legend from the title and leave it blank. Click Next.
This next screen allows us to change the properties of the legend box. Let's give our legend a grey background using the background color dropdown. Choose something neutral, like a light grey or light yellow. If we wanted to, we could add a shadow, change the border thickness, or add a larger or smaller gap between the legend content and border. Let's keep the defaults for these. Click Next.
The next two windows give us a lot of control over editing the appearance of the text and category boxes within our legend. The defaults should be fine for us. Click Next for the fourth box and Finish for the last one, and we'll see our legend inserted into our map.
Our legend gets inserted in a rather undesirable place, and it is unnecessarily skewed by the long name of the feature class and field being mapped. We can fix this by going to the Table of Contents and single clicking on the name of the feature, metros_2003, which will allow us to edit the name. Type in % Total Residents, as this describes what the legend is showing. Then click on the long field name below, and instead of typing something new, simply erase what is there and leave it blank. The size of our legend should adjust itself accordingly. Then you can drag the legend to the unoccupied lower left-hand corner of the map.
Does the text that we wrote in the legend adequately describe what we are showing in our map? We should probably iterate that the percentage is the percentage of state residents who moved to the state from another state in the past year. But that's a lot of information to jam into the legend box. It would probably be better to alter our title and add a subtitle to our map instead.
Alter the title by double-clicking on it. This will bring up the properties menu for the text. Tack " - 2006" on to the end.
Insert another title, and type something like "% residents who moved from outside the state within the last year". After you type in the text, you can adjust the font size by selecting the title, and then adjust the font and size in the drop down menus in the Drawing toolbar. Don't see the Drawing Toolbar? Add it by going to View > Toolbars > Drawing. At this point, you should have something that looks like Figure 12.
Adding Other Elements
We're making progress here. Let's add a few more elements. Go up to the Insert menu and choose North Arrow. Choose a simple arrow, insert it into our map, and find a good place for it.
!Don't choose something that looks "cute" or is elaborately ornate. Some of the exquisite compass roses that would look great on one of Christopher Columbus's navigational charts would look rather silly on your 2006 census map of urban migration.
Next, let's add a scale bar, by going to Insert, Scale Bar. In the first window you'll select a style. Make sure to edit the properties and change the units to something that makes sense, like miles or kilometers. Also reduce the number or divisions and subdivions a few notches - 3 divisions and 1 subdivision should be fine. Once you insert it on your map, select it and resize it so the numbers are not subdivided strangely. If it's hard to see what you're doing, use the Page Layout Zoom tools to zoom in to that area of the page, as depicted in Figure 13.
We should also add some text that describes the source of our data. Go to Insert > Text. Once the generic "Text" box is inserted, doubleclick on it to edit the contents. Type something like this on the first line "Data Source: American Community Survey 2006" and on the second line "Boundary Source: US Cartographic Boundary Files". Hit OK, and then reduce the size of the text. Make the font small, as this is just an explanatory note. It shouldn't distract attention away from our map.
When you are creating a map, you must consider design as well as utility. You are trying to send a message with your map; you are communicating visually with an audience. You could have the greatest dataset in the world and be a GIS wizard, but if you make crummy maps you will have ultimately failed. Position the elements on the page so they are balanced. Pay attention to the relationship between the elements - is the size of the title too big (a common mistake)? Does the color you chose for the legend clash with the map? In some cases, you may have to reconsider decisions you made back in the Data View. Does the classification scheme you chose for your data make sense? Do the colors display a pattern? Are they too light or dark? Too garish or plain? We don't have the time to delve into the aesthetics of cartography here, but take a look at some of the text resources listed in the Intro for a greater treatment of this subject.
ArcGIS does provide some tools to help you with the design process. If you placed your legend in the lower left-hand corner, your scale bar in the lower center portion, and the data source text in the lower right-hand corner, you'll want to make sure that they line-up evenly at the bottom. You could always "eyeball it", but it would be better to use the Align tools. Hold down the control (CTRL) key and select each of these elements. They should get hi-lighted in green. Then, do a single right click, and choose Align > Align Bottom. All of the selected elements will be aligned from the bottom, based on the location of the first element you selected. Notice you have several alignment options here.
Adding Labels Manually
One last item to add to our map before we're ready for the finished product. Some labels! Presently, it's hard to guess which cities are which, because none of them are labeled. We could add all of the labels to all of the cities at once, like we did in Part I. However, that would be a lot of labels and it may get confusing. Let's just add a few.
Instead of labeling (or even depicting) every single feature, we only label some prominent ones. Which features are prominent? That depends on the message you're trying to send - do you want to emphasize cities with high percentages of recent newcomers from out of state, or vice versa? In this case, let's say we want to hi-light the cities with a high percentage of newcomers, like Las Vegas, Phoenix, and Boise. We may also want to label large, well known cities that have small percentages of newcomers, like Los Angeles and Chicago. In cartography, this process is known as generalization.
To add labels to a city, just use the Insert Text tool. Type Las Vegas over the generic Text label. Change the font size and family using the option on the Drawing Toolbar. Drag the label for Las Vegas and place it to the right of the symbol for Las Vegas. Western convention is that you place the label to the right of the feature, unless it conflicts with other features or labels, or it causes the map to look unbalanced. You may want to use the Layout Zoom In tool to get a better look at where you're placing the label.
Once you have the first label finished, copy and paste it, and then edit it for the next city. This is much easier than inserting the text from scratch and reformatting the font size, family, color, and any other attribute you have changed.
As you add more labels to your map, you may add some that don't fit the criteria of your data. For example, New York is not at either end of the low or high scale, but you will want to add it to the map, since it is America's largest city and acts as a reference point. You may not consider adding Seattle, but may want to add it for the sake of balance, simply because that area of the map looks rather empty. You may end up omitting the names of some of the cities in South Carolina. Even though many of them are at the top of our classification scheme, they are bunched so tightly together that the names may be hard to read.
! You only want to add labels by hand if you are absolutely sure that your map is finished. These labels are just simple graphics - they are not tied to your features in any way. If you change the actual extent of your map the labels will NOT move with the geography, and you will have to manually reposition all of the labels. If you plan on labelling a lot of features on a maps that are part of dynamic, changing projects, then you probably do not want to add labels by hand.
Add a few more labels to get some practice working with the interface. Once you're finished, your map should like something like Figure 17.
Saving and Exporting Maps
So you've made a beautiful map that you want to share with the world. How do you go about sharing it? You can't send people your ArcGIS .mxd file. The mxd file works because it looks at all of the feature classes that you have stored in your geodatabase. You would have to send the mxd and the geodatabase and hope the links don't get broken. You're also assuming that the person you are sharing your map with has ArcGIS software (which could be unlikely) and that they know how to use it. Not the way to go.
Instead, you'll just want to export your finished map out as a simple format that is widely used. If you want a stand-alone file, an Adobe PDF is a good choice. If you plan on integrating the map with other media, say in a report within a word processing document or on a web page, you'll want to export the map as an image, like a tif or jpg. Let's say you want to export to a pdf file.
Go to the top menu, to File > Export Map. You'll see the screen in Figure 18.
Give your file a name, and in the dropdown menu (which has many options) choose PDF. Two things to note - if you were exporting this as an image file instead, you could adjust the resolution of the image with the sliding bar (higher resolution = bigger file size) and you could check the box in the lower-left hand corner to clip the image to the extent of the graphic to cut out whitespace. This doesn't apply to us here, since we are creating a pdf. Click the Format Tab, and select the Option that says Embed All Document Fonts. Then click Save and the export process will begin.
! It's important to embed document fonts when creating pdfs from maps. If you miss this step, there is a chance that map symbols and elements like the north arrow will not appear correctly on every computer. Fonts are handled locally by individual machines, and while the map may appear fine on your screen, it may appear strangely on someone elses.
Go to the folder where you saved your pdf file, click on it to open it, and take a look to make sure everything's a-ok. If so, congratulations! You have made your first map.
Of course, you could always send your map directly to a printer and make a paper copy. This is always a good idea, because what you see on the screen isn't always what you get on paper. There are differences in colors and shade based on the printer you are using, and based on how much ink or toner the printer has at a given time. You may also see imperfections that are not readily visible on a screen. Finally, if you plan to print or distribute a map in black and white - you should design it in black and white. If you design it in color and print in black and white, features and patterns that appeared legible in color on your screen may suddenly appear incomprehensible in black and white.
! Hey! In making our map we have completely excluded Alaska, Hawaii, and Puerto Rico! What gives? Since these areas are so distant from the rest of the continental US, it isn't practical to include them in one big map of the US, as it will force us to lose details about the lower 48 while we include vast uninhabited areas of ocean. This is why if you look at any standard US map, AK, HI, and PR get there own little boxes, with a projection and scale that is different from the continental US. We can create these in ArcGIS - if you look at the Table of Contents you will see a yellow label at the top that says Layers. We can actually add multiple Layers, and all of the features within each Layer would be separate from other Layers. In the Layout View, we will then get a box for each of these layers, allowing us to use a different scale and projection for each. We omitted this step in the interest of time, since we have a lot of material to cover.
Save your map, and move on to Part III when you're ready.