Graphing Tutorial William Hornick CS 101

Overview You will be given a brief description, example, and “how to create” for each of the following: You will be given a brief description, example, and “how to create” for each of the following: Bar Graphs Bar Graphs Line Graphs Line Graphs Circle Graphs Circle Graphs Scatterplots Scatterplots

Bar Graphs: Intro Shows the frequencies of specific data values in a data set. Shows the frequencies of specific data values in a data set. It can be used for categorical or numerical data. It can be used for categorical or numerical data. The length of the bar drawn for each data value represents the frequency of that value. The length of the bar drawn for each data value represents the frequency of that value. Bars may be drawn vertically or horizontally. Bars may be drawn vertically or horizontally. To avoid confusion, the bars should be the same width. To avoid confusion, the bars should be the same width.

Bar Graph: An Example

Bar Graph: Creating in Excel Click on an empty cell. Click on an empty cell. Go to Insert, then Bar under the Charts group. Go to Insert, then Bar under the Charts group. A white box will appear, click Select Data. A white box will appear, click Select Data. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. Add appropriate labels by editing the values in the select data source window. Add appropriate labels by editing the values in the select data source window. Title your graph, and label the vertical and horizontal axis from the Layout tab in the main window. Title your graph, and label the vertical and horizontal axis from the Layout tab in the main window.

Line Graph: Intro Typically used for continuous data to show the change in a variable (usually over time). Typically used for continuous data to show the change in a variable (usually over time). Each element of the sample is associated with an ordered pair, with a independent variable (such as time) and a dependent variable. Each element of the sample is associated with an ordered pair, with a independent variable (such as time) and a dependent variable. The independent variable is marked on the horizontal axis, and the dependent variable is marked on the vertical axis. The independent variable is marked on the horizontal axis, and the dependent variable is marked on the vertical axis. Each ordered pair is graphed, and are connected with line segments. Each ordered pair is graphed, and are connected with line segments. Scaling is critical when trying to analyze the relationship between the variables. Scaling is critical when trying to analyze the relationship between the variables.

Line Graph: An Example

Line Graph: Creating in Excel Click on an empty cell. Click on an empty cell. Go to Insert, then Line (with markers) under the Charts group. Go to Insert, then Line (with markers) under the Charts group. A white box will appear, click Select Data. A white box will appear, click Select Data. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. Add appropriate labels by editing the values in the select data source window. Add appropriate labels by editing the values in the select data source window. Title your graph, and label the vertical and horizontal axis from the Layout tab in the main window. Title your graph, and label the vertical and horizontal axis from the Layout tab in the main window.

Circle Graph: Intro Also called a pie chart. Also called a pie chart. Is a circle divided into parts (also called sections or wedges). Is a circle divided into parts (also called sections or wedges). Each part shows the percent of the data elements that are categorized similarly. Each part shows the percent of the data elements that are categorized similarly. The parts must sum to 100 percent. The parts must sum to 100 percent.

Circle Graph: An Example

Circle Graph: Creating in Excel Click on an empty cell. Click on an empty cell. Go to Insert, then Pie under the Charts group. Go to Insert, then Pie under the Charts group. A white box will appear, click Select Data. A white box will appear, click Select Data. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. With the cursor in the Data Range cells, click on the left most value of your data table, and drag to highlight to the right most data value. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. A graph should appear. Sometimes it is necessary to switch the Row/Column for desired structure. Add appropriate labels by editing the values in the select data source window. (A title should appear) Add appropriate labels by editing the values in the select data source window. (A title should appear) Under the Layout tab, select the Data Labels drop-down and select the appropriate labeling Under the Layout tab, select the Data Labels drop-down and select the appropriate labeling

Scatterplot: Intro Similar to a line graph, although the ordered pairs are not connected with line segments. Similar to a line graph, although the ordered pairs are not connected with line segments. Each element of the data set has two different measurements. Each element of the data set has two different measurements. The two coordinates of each point are determined by the two measurements for the corresponding element of the sample. The two coordinates of each point are determined by the two measurements for the corresponding element of the sample. This is the best way to determine if two characteristics are related. This is the best way to determine if two characteristics are related.

Scatterplot: An Example

Scatterplot: Creating in Excel Click on an empty cell. Go to Insert, then Scatter under the Charts group. Click on an empty cell. Go to Insert, then Scatter under the Charts group. A white box will appear, click Select Data. A white box will appear, click Select Data. Click Add under the Legend Entries Click Add under the Legend Entries Give your series a name Give your series a name With the cursor in the Data Range cells, click on the top of your column and drag to end highlighting all the data values for the Series X Values. Repeat for Y with other values With the cursor in the Data Range cells, click on the top of your column and drag to end highlighting all the data values for the Series X Values. Repeat for Y with other values Add appropriate labels by editing the values in the select data source window. (A title might appear) Add appropriate labels by editing the values in the select data source window. (A title might appear) Under the Layout tab, select the Data Labels drop-down and select the appropriate labeling Under the Layout tab, select the Data Labels drop-down and select the appropriate labeling

Graphing