Charts


Definitions


Recall a few basic definitions.

  • Data Series - A group of related data points plotted in a chart that originate from rows or columns on a single worksheet. Each data series in a chart has a unique color or pattern. You can plot one or more data series in a chart.

  • Axis - A line that borders one side of the plot area, providing a frame of reference for measurement or comparison in a chart.

  • Legend - A box that identifies the patterns or colors assigned to the data series or categories in a chart.

    Some types of charts


    There are a few major types of charts that we will deal with.

  • The Line Chart

          A line chart shows trends in data at equal intervals. This is especially useful to plot data that changes over time.






  • The XY Chart

          An XY chart either shows the relationships among the numeric values in several data series or plots two groups of numbers as one series of xy coordinates.




  • The Pie Chart

          A pie chart shows the proportional size of items that make up a data series to the sum of the items. A pie chart has only one data series.




  • The Bar Chart

          A bar chart illustrates comparisons among individual items. Categories are organized vertically, values horizontally, to focus on comparing values and to place less emphasis on time.




  • The Stacked Bar Chart

          A stacked bar chart shows the relationship of individual items to the whole.



    Creating charts


    In order to create a chart we use the Chart Wizard. The icon for the Chart Wizard is located on the Standard Toolbar.




    The Chart Wizard contains a series of four steps to create a chart. At each of these steps you can configure the appearance of your chart. At each stage of the Chart Wizard, you are allowed to stop and accept Excel defaults. You may do this by clicking the Finish button. By clicking the Next > button, you will be taken to the next step of the Chart Wizard.

  • The first question you may answer is what type of chart you want to create.

    If you select each type of chart, then to the right you will see sample charts.

    If you select one of them, then you will see a short description about the chart.

    If you select and hold the button labeled Press and hold to view sample, then you will see a sample of how the data ranges you have selected will appear in the selected chart.

    Notice at this point like in the first three questions of the Chart Wizard, you have three options.

    1. You can make a choice, and then click the button labeled Next >, and you will be taken to the next question in the Chart Wizard.

    2. You can just simply click the button labeled Next >, and the Excel default answer to the current question will be accepted, and you will be taken to the next question in the Chart Wizard.

    3. You can also click the button labeled Finish, and this will allow you to accept the Excel defaults for all subsequent questions in the Chart Wizard, and the chart will be drawn.

    In all questions except the first, you also have the option of clicking the button labeled < Back. This will take you to the previous question in the Chart Wizard.




  • The second question you may answer is what data series you want to use as the source for the chart.




  • The next question you may answer is about Chart Options. Here you can make choices about the Chart Title, Axes, Gridlines, Legend, Data Labels, and Data Table.




  • The last question you may answer is about Chart Location.




    To draw the chart, click the button labeled Finish.

    Sample Spreadsheets to use to draw charts


  • Line Chart

  • XY Chart

  • Pie Chart

  • Bar Chart and Stacked Bar Chart

    Creating a default chart without going through the Chart Wizard


    In order to draw a chart without going through the Chart Wizard, you may use the F11 key. After you have selected your data ranges, if you hit the F11 key, then a default chart will be drawn.

    The default chart type is a column chart. If you draw a particular kind of chart frequently, then it might be useful to you to set that chart type as the default. To do that, simply draw any chart, and then right click inside the chart, and you will get a quick menu. One of the options is Chart Type.... If you select this option, then you will see the following dialog box.




    To change the default chart type, choose the type of chart you want to be the default, and then click the button labeled Set as default chart.

    Modifying a Chart


    There are many ways to modify a chart. We will discuss a few of them.

    An example of Object Linking


  • Recall that Object Linking means that we place a reference to our source data in the destination. That is, if we wish for a Microsoft Word document to contain a chart we created in Excel, and simultaneously we want to use that chart in for instance a PowerPoint demonstration, we would place a link to the chart we create in Excel. Then any change that we make to the chart in Excel will also happen in Microsoft Word and Powerpoint simultanesouly.

  • Note that this is much different that Object Embedding in which we simply make a copy of our source object and embed that in our destination.

  • You may use this sample data to see the effects of Object Linking.

    1. Draw the chart in Microsoft Excel

    2. Open a new Microsoft Word document and type the following: "This is the sine function.".

    3. Add a few blank lines in the document by hitting the Enter key.

    4. Go back to Microsoft Excel and select the chart you have drawn. (That is, click inside the chart until the sizing handles appear around the chart.)

    5. Go to the Edit Menu and choose Copy. This will place the Chart Object on the clipboard.

    6. Go to the Microsoft Word document.

    7. Go to the Edit Menu and choose Paste Special.

    8. In the dialog box that appears choose Paste link.

    9. Click OK.

    10. Go back to Microsoft Excel. Change any of the data in the data ranges you used to draw the chart. Notice that not only will the change take place in the chart you drew, but it will also take place in the Microsoft Word document.

    A Sample Spreadsheet


    The following example was born out a question that is commonly asked near the end of a quarter or semester: "What do I need to make on the Final Exam in order to get an A for the course?"

    Recall the way your final grade is calculated.

    Exam 1 25 %
    Exam 2 25 %
    Project 1 7.5 %
    Project 2 7.5 %
    Final Exam 35 %


    If you receive a score of 100 on all exams and projects, then your final course grade will be 100. Since you have your scores on the first two exams and project 1, you can calculate a portion of your grade.


    Exercise


    You may take 20 minutes to work on this exercise. You may work in groups of two. Those who finish the exercise may earn up to 2 additional points to their Spreadsheet Project grade.

    The requirement of the exercise is to develop a template which will allow a person to input the grades they have made so far, and determine what they need to make on the Final Exam in order to achieve an A, B, C, or D for the course. Recall the grading scale.


    90 <= x < 100 A
    80 <= x < 90 B
    70 <= x < 80 C
    60 <= x < 70 D


    Consider the following example. Suppose Fred has made the following scores this semester.


    Exam 1 100
    Exam 2 70
    Project 1 60
    Project 2 80


  • So he has accumulated 100*0.25+70*0.25+60*0.075+80*0.075=53 points.

  • Notice that the total possible points for the exams and projects is 65.

  • Now Fred would like to know what he would need to make on the Final Exam in order to receive 90 points or better (an A).

  • So we take the total number of points required for an A, 90 points, and substract the total he has from all exams and projects except the Final Exam, 53.

  • So he needs 37 points out of the Final Exam in order to recieve an A for the course.

  • Notice that the number of points Fred will get from his Final Exam grade is determined by multiplying the score he gets on the exam by 0.35.

  • So we have Score * 0.35 =37. So Score = 37/0.35 = 105.7143.

  • So Fred would need to score between 105 and 106 on the Final Exam in order to make an A for the course.

    In order to receive the points, you must make

  • a print out of your template with formulas displayed

  • a print out showing your calculations for what a student needs to make on the Final Exam in order to recieve an A, B, C, or D for the course.

    Make sure to print the names of both members of your team on the printouts.

    Notice that you can use your work to determine what you need to make on the Final Exam in order to receive the grade you want for the course.