When do you use line plot

Line graphs can be constructed manually, or by using software, such as Microsoft Excel, which greatly improves the speed, and accuracy, of the end product. Line graphs consist of two axes: x-axis horizontal and y-axis vertical. Each axis represents a different data type, and the points at which they intersect is 0,0. The x-axis is the independent axis because its values are not dependent on anything measured. The y-axis is the dependent axis because its values depend on the x-axis's values.

Each axis should be labeled according to the data measured along that axis. Then, each axis should be divided in appropriate increments e. For example, if measuring the changes in a stock's prices for the previous two weeks, the x-axis would represent the time measured trading days within the period , and the y-axis would represent stock prices.

When using line graphs to track the price of a stock, the data point most commonly used is the closing price of the stock. Each data point is plotted and connected by a line that visually shows the changes in the values over time. If the value of the stock increased daily, the line would slope upward and to the right. Conversely, if the price of the stock was steadily decreasing, then the line would slope downward and to the right.

Line graphs are used to track changes over different periods of time. Line graphs can also be used as a tool for comparison: to compare changes over the same period of time for more than one group. A line graph is a graphical display of information that changes continuously over time. Within a line graph, there are various data points connected together by a straight line that reveals a continuous change in the values represented by the data points.

Line graphs are useful in finance because they are very effective at creating visual representations of trends over time. For this reason, they are often used to depict how a stock is performing over a specific period of time. Graph theory is a mathematical discipline. Graph theory specifically studies graphs, mathematical structures that are used to model pairwise relations between objects.

In graph theory, a line graph is also called a covering graph, the derivative, the edge-to-vertex dual, the conjugate, the representative graph, the edge graph, the interchange graph, the adjoint graph, and the derived graph. This is the formal definition of a line graph: Given a graph G , its line graph L G is a graph such that each vertex of L G represents an edge of G, and two vertices of L G are adjacent if their corresponding edges share a common endpoint in G.

A line graph is the intersection graph of the edges of G , representing each edge by the set of its two endpoints. You can use a line graph in Excel to display trends over time. In Excel, line graphs are appropriate if you have text labels, dates, or a few numeric labels on the horizontal axis x-axis. Here are the steps to create a line graph in Excel. If you are using numeric labels, empty cell A1 before you create the line chart :. In Google Sheets, creating a line graph can help you identify trends in data over time.

Here are the steps for formatting your data in Google Sheets so you can create a line graph:. For more information about how to customize your line chart, Google provides a help center for all of its tools, including Google Sheets.

Addison Wesley. Accessed June 8, Excel Easy. When we look at line graphs, we compare the lines to each other more than their height from the x-axis. By their nature, line graphs are better at showing the change of values over time than an exact quantity at each measured point. Line graphs, therefore, are not required to have a zero baseline; but in most cases, it is still advisable. It is less confusing to an audience if the y-axis starts at zero, since that is the normal expectation when seeing a chart for the first time.

There should be compelling reasons to subvert those expectations. Here are some specific cases for which a zero baseline might not be optimal:. If our y-axis went all the way down to zero, these meaningful fluctuations would be impossible to perceive. Our graphs should include a range of reasonable values, providing the most meaningful context to a viewer.

It might be important to include a horizontal line as a reference point for zero, but no data series on our graphs should cut across either of our axes. The specific answer to this question will vary with each graph you make. From there, you can modify your axis range, and the position of the line or lines plotted on the graph, to suit your specific needs.

The storytelling with data community would be a great place to start! Try any or all of these quick exercises:. You could also look back on some of our prior SWDchallenges, like this one about annotated line graphs , to see what some of your fellow communication enthusiasts have created. Or, continue your journey through our full what is…?

How does a line graph work? What kind of data can be used on a line graph? DO: Show a line of sales by month. How many different lines can I put in one chart? Does the y-axis of a line graph have to start at zero?

This is often the case with larger units of time, such as weeks, months, and years. Since we have a second independent variable, some sort of coding is needed to indicate which level year each line is. We will need a legend to explain the coding scheme. Multiple line graphs have space-saving characteristics over a comparable grouped bar graph.

Because the data values are marked by small marks points and not bars, they do not have to be offset from each other only when data values are very dense does this become a problem.

Another advantage is that the lines can easily dual coded. With bars, shape coding cannot be used, and pattern coding has to be substituted. Pattern coding tends to be much more limiting. Because the data point for September is missing, the line should not be connected between August and October since this would give an erroneous local slope.

This is particularly important if you display the line without symbols at individual data points. One Independent and One Dependent Variable Scatter Plot With a scatter plot a mark, usually a dot or small circle, represents a single data point. Return to Top Line Graph Line graphs are like scatter plots in that they record individual data values as marks on the graph. Specific tips for line graphs The graphing tutorial gives specific instructions on creating scatter plots and regression lines Line graphs can be created with either the Line Graph type or with XY Scatter.

It is simpler to create a line graph with XY Scatter when your independent and dependent variables are in columns. Marks for data points are called Markers The color and size of the line and markers can be set by double-clicking on the line in the graph.