Tutorial: Creating a line graph
Creating line graphs are useful in visualising trend of a data series over time such as that for showing trend of admissions-over-time
For this exercise, we will use the data on admissions-over-time
data as an example (see Table 1
Admissions-over-time data for a CMAM program in Somalia
First thing to do is to enter the data in a spreadsheet. For this exercise, we will use OpenOffice Calc
as our spreadsheet software. Here, we create a table with two columns, the first for the month and the second for the number of admissions corresponding to that month (see Figure 1
Creating a table of monthly admissions data
Next, click on the chart button on the menu ribbon as shown in Figure 2
. If the chart button is not visible, click on the 'Insert' option and click on the 'Chart...' option in the drop-down menu that will appear (see Figure 2a
and Figure 2a
: Initiating the chart function
Once the chart function is initiated, a 'Chart Wizard' pops out which shows a set of chart types that can be created. For this exercise, we will select 'Line' and will further select the option to of 'Lines Only' which will create a line graph without markers for the data points (see Figure 3
). Click 'Next'.
Selecting line chart type option
Now we need to select the data range to use for the line graph. In the wizard, there is an option of either entering the data range by hand in the entry field asking for a data range or by specifying the data range by highlighting the fields on the spreadsheet containing the data. For this exercise, we will do the second option by clicking on the button at the right of the data range field which when hovered on will prompt a tooltip saying 'Select data range' (see Figure 4
). Once clicked, we can now highlight on the spreadsheet the data fields we want to graph (see Figure 4a
). Once highlighted, we will see that our line graph is already taking shape in the graph window.
and Figure 4a
Selecting data range to graph
The next steps are for specifying labels and other parameters of the line graph (e.g., axis labels, legends, grids). First, we need to specify the range of values for the names of the data points on the line graph. This is either the headings of the columns (if data was tabulated in columns) or the row names (if the data was tabulated by rows). Since our data was tabulated in columns, we select the range for the names as the headings of the data columns which in this case are 'Months' for the first column and 'Admissions' for the second column. These values can be selected in a similar fashion as the selection of the data series to graph by either entering the range of values in the spreadsheet on the entry field called 'Range for Name' or by clicking on the button beside the entry field which when hovered on gives a tooltip prompting to 'Select data range' (see Figure 5
). Then click on 'Next'.
Selecting range of names for the data series
The last step is specifying the title of the graph and the x- and y-axis labels and whether or not to display a legend. Simply input the corresponding text that we would like to appear on these labels on the appropriate entry fields to create a title and labels. As for the legend, by default the chart wizard includes a legend. However, given that we are graphing only 1 data series, the convention is to not put a legend on the graph. So, this option should be unselected (see Figure 6
Specifying title of graph, x- and y-axis labels and a legend.
We click on finish and we now have a line graph of admissions-over-time.
For further tutorials on using OpenOffice Calc for creating tables and graphs, visit the Tutorials for Open Office