Line chart
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In the physical sciences, tables of data collected from experiments on physical processes are often visualised through the use of a particular graph, sometimes called a line chart.
For example, if one were to collect data on the speed of a body at certain points in time, a table such as the following might be produced.
| Elapsed Time (s) | Speed (ms-1) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 7 |
| 3 | 12 |
| 4 | 20 |
| 5 | 30 |
| 6 | 45 |
Understanding the process described by the data in the table is aided by producing a graph or line chart of Speed versus Time. In this context, Versus (or the abbreviations vs and VS), separates the parameters appearing in an X-Y (two-dimensional) graph. The first argument indicates the dependent variable, usually appearing on the Y-axis, while the second argument indicates the independent variable, usually appearing on the X-axis. Thus the graph of Speed versus Time would plot time along the x-axis and speed up the y-axis. Mathematically, if we denote time by the variable t, and speed by v, then the function plotted in the graph would be denoted v(t) indicating that v (the dependent variable) is a function of t.
By plotting each point in the table, and joining successive points with a straight line, a graph such as the one shown can be produced.
Such a visualisation can reveal physical relationships. One can quickly and intuitively understand the behaviour described by the data. Further, measurements such as the gradient or the area under the curve can be made visually, leading to more conclusions from the data.
