Charts and Graphs

The preparation, publication, and presentation of graphs and charts represent a significant portion of engineering practice. In Excel, a majority of such displays are given the designation of x–y scatter graphs. This chapter discusses the bar graphs, column graphs, and surface (3-D) charts. When a trend line is added to a chart, Excel automatically calculates its R² value. R² is called the coefficient of determination, whereas R is called the correlation coefficient. The chapter provides six scatter plots of a set of hypothetical experimental data displayed in the upper-left corner of the sheet. Moving averages are employed as forecasting tools in applications ranging from stock market predictions to estimations of sales and inventory trends. Most charts prepared for engineering purposes will have a simple format involving minimal artistic or cosmetic effects. The chapter then illustrates the format windows that may be called up to make adjustments in various chart layouts and appearance.