Interacting with Tabular Data
Tabular information is the basis of geographic features, allowing you to visualize, query, and analyze your data. In the simplest terms, tables are made up of rows and columns, and all rows have the same columns. In ArcGIS, rows are known as records, and columns are fields. Each field can store a specific type of data, such as a number, date, or piece of text. We learned that feature classes are really just tables with special fields that contain information about the geometry of the features. This session will introduce you to common table-related tasks.
Goals
In this tutorial, you will learn to:
Open tabular data
Sort records in a table
Filter data in the table
Add a field
Calculate field
1. Start a new project
In order to get started, you must first create a project. As you learned so far, a project contains maps, layouts, tasks, and connections to servers, databases, tools, and folders.
Go to the Start menu and open ArcGIS Pro and sign in using your Clemson ID.
To do this, click the Sign In menu at the top corner.
Click on Enterprise login. In the Your ArcGIS organization’s URL box, enter clemson so that your URL reads: clemson.maps.arcgis.com. Select Continue.
A new window appears. Click on Clemson University.
The Clemson University regular login screen appears. Enter your Clemson username and password.
ArcGIS Pro automatically opens the start page. Here you find options to either open an existing project or create a project using one of the available templates. These templates provide a starting point for the project. Additional maps, scenes, and catalog views can be added to your project at any time, regardless of the initial template.
On the start page, under Blank Templates, click Map.
On the Create a New Project dialog box, in the Name box, type Interacting_with_Tabular_Data.
To save a project to a different location click the Browse button and browse to the folder Working_with_Tabular_Data on the C Drive.
2. Connect to folder and add data to your map
Under the Catalog pane right-click Folders and click Add Folder Connection . Navigate to :\\Working_with_Tabular_Data and click Ok.
The folder connection appears in the Catalog pane in the Folders category .
Under the Catalog pane click on Project, expand Folders and then expand Working_with_Tabular_Data and expand TabularData.gdb. Right-click on Counties_demographics and add it to your map.
3. Set the coordinate system for your map
When you start a new GIS project, it is very important to work in the right coordinate system. In our case, we are going to work with data in the continental United States. According to the coordinate systems section we covered, which coordinate system would be more appropriate for this project: geographic or projected?
Since in this exercise, we want to look at the density of the COVID19 cases and population in each county, we will need to use a coordinate system that preserves the area.
In order to set up the correct coordinate system, go to the Contents pane, right-click on Map.
Click Properties.
The Map Properties dialog box opens. Click the Coordinate Systems tab.
The boxes below the Current XY and Current Z headings show the current horizontal and vertical coordinate systems of the map or scene, respectively.
Click Details for the horizontal coordinate system to see how it is defined. As you see described, your map has the WGS 1984 Web Mercator Auxiliary Sphere as the default projected coordinate system.
To change the horizontal coordinate system, click the button below the Current XY.
The XY Coordinate Systems Available box shows you the current system and all the possible available options under:
Layers
Geographic coordinate system
Projected coordinate system
You have to choose an appropriate coordinate system from the corresponding Coordinate Systems Available list. You can also enter a search term in the Search box to help locate a specific coordinate system.
In our case, we want to select a projected coordinate system, so we expand the Projected Coordinate System dropdown.
Click on Continental.
Expand the North America tab.
Click on North America Albers Equal Area Conic.
Click Ok.
4. Open attribute table and inspect the data
Under the Catalog pane click on Project, expand
Folders and then expand Working_with_Tabular_Data and expand TabularData.gdb. Right-click on Counties_demographics and add it to your map.
Right-click on the Counties_demographics in the Content page.
Click Attribute Table .
Right-click on 2019 Total Population and click on Sort Ascending
.
What is the least populated county in the United States? What is the most populated one?
5. Filter your data
Filtering your table provides a way to work with and focus on a subset of records. Here, we will show you two ways of filtering your data: showing selected records, and using a definition query.
Show selected records
To interact with selected records only, consider switching the table display to the Show selected records mode. In Show selected records mode, the table view will only list those records that have been selected in the table. You can always change your selection either by updating the currently selected features in the map corresponding to the open table, or by changing your selection in the table. The able will dynamically update to reflect the current selection set. Using what you learned, click on a part of your map to select several counties.
Right-click on Counties_demographics in the Contents pane and click Attribute Table .
At the bottom of the open table, click Show selected records
.
Use a definition query
Another way to filter the list of records in the table is to define a query expression.
To create a new definition query, do the following:
Right-click on Counties_demographics in the Contents pane to open the Properties
dialog box.
On the Properties dialog box, click the Definition Query page.
Click Add Clause.
Build an expression to define the subset of records and features you want to see. Pick a state and query the counties within that state.
Click Add to add the expression. Click OK to close the dialog box.
To remove a definition query, right-click on Counties_demographics in the Contents pane. On the Data tab, in the Definition Query group, change the drop-down list setting to <None>.
6. Add and calculate a new field
Let's assume we want to know the population density of each county. We already have an automatically generated field called Shape_Area--which shows the area of each record in the map unit.
What is the map unit?
Let's add a field that contains the area of each county in square miles. To do so, we need to first add a field. For this, we will use Fields view. In Fields view, you can edit a table's fields and modify field properties, delete fields, or create fields.
To open the Fields view, right-click a column heading in the table and click Fields. You can also click Add Field from the table view's built-in toolbar to directly open the Fields view to add a new field.
For the Field Name, type Area_SQMI.
For the Data Type, choose Double.
Click Save.
Right-click on Area_SQMI, and Calculate Geometry.
Under Property, and Area.
Click on Coordinate System, and click North America Albers Equal Area Conic.
Click on Run.
7. Visualize data using charts
A chart is a graphical representation of data. Visualizing data through charts helps to uncover patterns, trends, relationships, and structure in data. You can use charts together with maps to explore your data and help tell a story.
Charts can be created from both tabular and raster data, and a different set of charts are available for each data type. In ArcGIS Pro, you can do the following:Make a chart of any map layers with tables, rasters, or standalone tables.
Interact with charts to explore your data dynamically across related maps, tables, and other charts created from the same layer.
Change a chart's appearance and save or apply custom format themes.
Share a chart by exporting it as a graphic, adding it to a layout, or by packaging its source layer, map, or project.
Add COVID19 dataset to your map. Right-click on the layer.
Click on Create Chart.
Clcik on Bar Chart .
Under Category or Date, Click on Province/State.
Under Numeric field(s) check the box next to Confirmed.
Click Apply.
Sorting charts
8. Excercise on your own
Add another field for population density to Counties_demographics. Symbolize the new density field using what you have learned so far.
Bar charts are automatically sorted alphabetically by their categories (x-axis ascending). This can be changed using the Sort options in the chart window.
Four options are available:
X-axis Ascending—Categories are arranged alphabetically from left to right.
X-axis Descending—Categories are arranged in reverse alphabetical order.
Y-axis Ascending—Bars are arranged by value (height) from smallest to largest.
Y-axis Descending—Bars are arranged by value (height) from largest to smallest.
Here, we will use Y-axis Descending.
Exporting charts
Charts can be exported as a graphic file using the Export button in the chart window. SVG, JPG, and PNG formats are supported. Specify the corresponding extension (.svg, .jpg, or .png) to control the type of exported graphic file.
Charts can also be added to a layout as a chart frame.
Congratulations, you are done with this part!