# Multiple line graph

Command: | Graphs Multiple line graph |

## Description

Creates a graph that shows consecutive observations of different variables.

## Required input

Select the variables of interest, and optionally a filter to include only particular cases in the graph.

Also you can enter a variable containing labels for the X-axis (e.g. dates).

**Options**

**Logarithmic transformation**: if the data require a logarithmic transformation (e.g. when the data are positively skewed), select the Logarithmic transformation option.**Complete cases only**: a case (spreadsheet row) will only be included in the graph when data are available for all variables.**Markers**: mark observations in the graph.**Trend line**: option to plot one of the following trend lines:**Moving average trend line**: option to plot a moving average trend line for each variable.

A moving average trendline smoothes out fluctuations in data to show a pattern or trend more clearly. A moving average trendline uses a specific number of data points (set by the**window width**option), averages them, and uses the average value as a point in the trendline. If**window width**is set to 3, for example, then the average of the first 3 data points is used as the first point in the moving average trendline. The average of the 2nd, 3^{rd}and 4^{th}data points is used as the second point in the trendline, and so on.**LOESS smoothing**: option to plot a LOESS (Local Regression Smoothing) trendline. The degree of smoothing is controlled by the**span (%)**which is the proportion (expressed as a percentage) of the total number of points that contribute to each local fitted value. Larger values result in smoother trendlines.**Isotonic regression curve**:- in case the tendency of the data is increasing: a fitted free-form line that is non-decreasing everywhere, and lies as close to the observations as possible
- in case the tendency of the data is decreasing: a fitted free-form line that is non-increasing everywhere, and lies as close to the observations as possible

## Example

## See also

- Multiple comparison graphs
- Clustered multiple comparison graphs
- Multiple variables graphs
- Clustered multiple variables graphs
- Format graph
- Graph legend
- Add graphical objects
- Reference lines

## External links

- Local regression (LOESS smoothing) on Wikipedia.
- Isotonic regression on Wikipedia.
- Moving average on Wikipedia.