Chapter 5 EXCEL Graphing Data

Intro In EXCEL graphs are referred to as CHARTS. We will do 2-D graphs known as Scatter Charts or X-Y Charts. Vocabulary: abscissa (x-axis), ordinate (y-axis), horizontal axis (Category Axis), vertical axis (Value Axis). Note that for XY Charts the horizontal axis is also called the Value Axis.

Sec 5.1 – Characteristics of a Good Graph Must convey information clearly and unambiguously. Usually need a title, clearly labelled axes, units. Uncluttered, readable grid.

Good example of a line drawn through data points TimeVoltage

Two different data sets Voltage TimeDevice ADevice B

Create a Graph in EXCEL – Sec Select block of contiguous cells containing the data to be plotted. 2. Choose the chart type based upon the preview given. 3. Edit individual objects such as axis label or or legend as needed from the ribbon tab or by right clicking. 4. Add objects as needed from the ribbon LAYOUT tab.

Notes on Charts Select an x-y graph for paired data. Select a line graph, bar graph, pie chart for valued data (y-values only). Can move charts from one worksheet to another by selecting the chart and then using Cut (or Copy)

Sec 5.3: X-Y GRAPHS (EXCEL Scatter Charts or XY Charts) Create an X-Y Graph using example on pages After entering the data and choosing the Scatter Chart we get:

Edit the Graph Remove the legend Format data series to use a black line and blue points. (right click on a data point). Choose Primary Line for Series Option and Choose Solid Line for Line Color.

Edit the Graph Add major gridlines if needed (right-click on a value on horizontal axis). Format the axis (right click on a value on the axis, then choose appropriate option). Enter a title (Layout Tab, chart title). Enter axis names (Layout Tab, axis)

Viola!

5-4: Adding Data to Existing Chart Add additional data points. If these fall within the data range, they will automatically be added to the chart. If outside the range, then enlarge the chart by dragging the handles (small black squares) so that the data points appear.

Adding Additional Data – 2 graphs on same chart Activate the chart. Note that the data is also selected. Simply drag the lower right handle to include the other column of data. Can add data that is non-adjacent. Hold down CTRL key while choosing.

Assignment Classwork: Problem 5.2 Homework: Problem 5.3, 5.7

Sec 5.5: Semi-Log Graphs Plotting x or y on a logarithmic scale is equivalent to plotting log x or log y on an arithmetic scale. Semi-log has a logarithmic scale for the ordinate (y-axis) and an arithmetic scale for the abscissa (x-axis). All y-values must be greater than zero.

Semi-log Use when y-values span several orders of magnitude. Use for exponential equations b/c the semi- log graph plots as a straight line and is easier to interpolate visually. Works for all bases of logarithms. In EXCEL, LN(x) is for base e, LOG10(x) is for base 10.

Assignment Classwork: Prob 5.10 Homework: Prob 5.9

Sec 5.6 Log-Log Graphs Has log coordinates on both axes. Very useful for POWER EQUATION y=ax b because plots as a straight line. Very useful when data spans several orders of magnitude on both axes. Example is Volume of a Sphere where V=(4/3)πr 3.

Assignment Classwork: Prob 5.11 Homework: Prob 5.13

Sec 5.7 – 5.9 Line Graphs Used for SINGLE-VALUED data like for example the high temperature each day for a week. The data points are always plotted and then connected with straight lines (not a smooth curve). Create like an XY graph but choose line graph.

Assignment Classwork: Prob Homework: Prob 5.17

Bar Graph Used for single-valued data like a line graph. Uses a series of vertical rectangles (bars). Easier to read than a line graph.

Assignment Classwork: Prob Homework: Prob 5.21

Sec 5.9 Pie Charts Shows distribution of items within a data set. Represent single-valued data. Can also calculate percentages and display on the graph. NO CLASSWORK OR HOMEWORK