Charts in OpenOffice Calc

Charts in OpenOffice Calc

Introduction

Charts and graphs can be powerful ways to convey information to the reader through a pictorial representation. Open Office Calc offers a variety of different chart and graph formats for data. Using Calc, customization of charts and graphs to a considerable extent. This facility enhances the presentation of data in an effectine manner. Many of these options enable to present information in the best and clearest manner.

Familiarization with the types of charts

There are various charts graphs representing data through relevant pictorial representation. The creation and presentation of charts are discussed in the following sections.

It is important to remember that while data can be presented with a number of different charts, the messages to convey to audience dictates the chart ultimately use. The following sections present examples of the types of charts that Calc provides.

1. Column charts

2. Bar charts

3. Pie charts

4. Area charts

5. Line charts

6. Scatter or XY charts

7. Bubble charts

8. Net charts

9. Stock charts

10. Column and line charts

Column Charts

This type shows a bar chart or bar graph with vertical bars. The height of each bar is proportional to its value. The x-axis shows categories. The y-axis shows the value for each category.

Normal type is a sub-type shows all data values belonging to a category next to each other. Main focus is on the individual absolute values, compared to every other value.

Stacked type is a sub-type shows the data values of each category on top of each other. Main focus is the overall category value and the individual contribution of each value within its category.

Percent is a sub-type shows the relative percentage of each data value with regard to the total of its category. Main focus is the relative contribution of each value to the category's total.

Bar Charts

This type shows a bar chart or bar graph with horizontal bars. The length of each bar is proportional to its value. The y-axis shows categories. The x-axis shows the value for each category.

Pie Charts

A pie chart shows values as circular sectors of the total circle. The length of the arc, or the area of each sector, is proportional to its value.

Normal Pie is a sub-type shows sectors as colored areas of the total pie, for one data column only. In the created chart, you can click and drag any sector to separate that sector from the remaining pie or to join it back.

Exploded pie is a sub-type shows the sectors already separated from each other. In the created chart, you can click and drag any sector to move it along a radial from the pie's center.

Doughnut is a sub-type can show multiple data columns. Each data column is shown as one doughnut shape with a hole inside, where the next data column can be shown. In the created chart, you can click and drag an outer sector to move it along a radial from the doughnut's center.

Exploded doughnut is a sub-type shows the outer sectors already separated from the remaining doughnut. In the created chart, you can click and drag an outer sector to move it along a radial from the doughnut's center.

Area charts

An area chart shows values as points on the y-axis. The x-axis shows categories. The y-values of each data series are connected by a line. The area between each two lines is filled with a colour. The area chart's focus is to emphasise the changes from one category to the next.

Normal - this sub-type plots all values as absolute y-values. It first plots the area of the last column in the data range, then the next to last, and so on, and finally the first column of data is drawn. Thus, if the values in the first column are higher than other values, the last drawn area will hide the other areas.

Stacked - this sub-type plots values cumulatively stacked on each other. It ensures that all values are visible, and no data set is hidden by others. However, the y-values no longer represent absolute values, except for the last column which is drawn at the bottom of the stacked areas.

Percent - this sub-type plots values cumulatively stacked on each other and scaled as percentage of the category total.

Line charts

A line chart shows values as points on the y-axis. The x-axis shows categories. The y-values of each data series can be connected by a line.

Points only - this sub-type plots only points.

Points and lines - this sub-type plots points and connects points of the same data series by a line.

Lines only - this sub-type plots only lines.

3-D lines - this sub-type connects points of the same data series by a 3-D line.

Scatter or XY charts

An X-Y chart in its basic form is based on one data series consisting of a name, a list of x values, and a list of y values. Each value pair (x|y) is shown as a point in a coordinate system. The name of the data series is associated with the y values and shown in the legend.

The chart is created with default settings. After the chart is finished, you can edit its properties to change the appearance. Line styles and icons can be changed on the Line tab page of the data series properties dialogue box.

Double-click any data point to open the Data Series dialogue box. In this dialogue box, you can change many properties of the data series.

For 2-D charts, you can choose Insert - y-Error Bars to enable the display of error bars.

You can enable the display of mean value lines and trend lines using commands on the Insert menu.

Points only

Each data point is shown by an icon. OpenOffice uses default icons with different forms and colours for each data series. The default colours are set in Tools - Options - Charts - Default Colours.

Lines Only

This variant draws straight lines from one data point to the next. The data points are not shown by icons.

The drawing order is the same as the order in the data series. Mark Sort by x-values to draw the lines in the order of the x-values. This sorting applies only to the chart, not to the data in the table.

Points and Lines

This variant shows points and lines at the same time.

3-D Lines

The lines are shown like tapes. The data points are not shown by icons. In the finished chart choose 3-D View to set properties like illumination and angle of view.

Bubble charts

A bubble chart shows the relations of three variables. Two variables are used for the position on the x-axis and y-axis, while the third variable is shown as the relative size of each bubble.

The Data Series dialog box for a bubble chart has an entry to define the data range for the Bubble Sizes.

Net charts

A Net chart displays data values as points connected by some lines, in a grid net that resembles a spider net or a radar tube display.

For each row of chart data, a radial is shown on which the data is plotted. All data values are shown with the same scale, so all data values should have about the same magnitude.

Column and line charts

A Column and Line chart is a combination of a Column chart with a Line chart. Select one of the variants

• Columns and Lines. The rectangles of the column data series are drawn side by side so that you can easily compare their values.

•Stacked Columns and Lines. The rectangles of the column data series are drawn stacked above each other, so that the height of a column visualises the sum of the data values.

You can insert a second y-axis with Insert - Axes after you finish the wizard.

Creating and formatting charts

1. Select the cells that contain the data that you want to present in your chart.

2. Click the Insert->Chart option or click Insert Chart icon  on the Standard toolbar.

3. The Chart Wizard has three main parts:

• List of steps involved in setting up the chart,

• List of chart types, and

• The options for each chart type.

At any time you can go back to a previous step and change selections.

4. Choose a Chart type and its option type. Then click Next button.

5. In Step 2, Data Range, manually correct any mistakes made in selecting the data. Click one of the options for data series in rows or in columns. Check whether the data range has labels in the first row or in the first column or both. Then click the Finish button, or click Next to change some more details of the chart.

6. In the Data Series list box contains a list of all data series in the current chart.

•  To organize the data series, select an entry in the list.

• Click Add to add another data series below the selected entry. The new data series has the same type as the selected entry.

• Click Remove to remove the selected entry from the Data Series list.

• Use the Up and Down arrow buttons to move the selected entry in the list up or down. This does not change the order in the data source table, but changes only the arrangement in the chart.

• Then click Next button

7. On the Chart Elements page, chart a title and, if desired, a subtitle. Use a title that draws the viewers’ attention to the purpose of the chart: what you want them to see. For example, a better title for this chart might be Mark Statement. Then click Finish to create chart..

Case Study: Create a spreadsheet file to store sales data of a particular product and present as Chart.