15 Charts

This chapter explains how to create charts from data that you have entered in your worksheet.

It includes sections on:

Creating a chart

The first step in creating a chart is to enter or compute your data within a worksheet.

Preparing your data

There are ways to organise your data to make it easier to build a chart.

Making the chart

Follow this process to make your chart:

  1. Chart tool button Select the range of data you want to include in the chart, and click the Chart tool button on the toolbar. The data must include some number cells.
  2. The chart menu will appear, from which you should choose the type of chart you want.
  3. A dialogue box for that type of chart will appear. Choose the type you want by clicking on the icons, and enter any other details necessary in the dialogue box.
  4. Click Create. Your chart will be generated and appear on the worksheet in its own frame, just beneath the data on which it was based. In some cases (such as low-resolution screen modes) this may be off the screen.

Types of chart

Fireworkz provides several different types of chart for you to use in your documents. The following options are available:

Each type is described in turn in the next few sections. Each basic option contains several different versions of the chart type, so that a wide variety of charts can be generated.

Bar charts

Bar charts display data as a series of bars measured against an axis. A variety of types of bars are available in Fireworkz, including pictograms and three-dimensional bars. When you choose the Bar option on the Chart menu, the Bar chart dialogue box will appear.

  1. Click the image button representing the type of chart you want.
  2. Select the 3-D option if you want a three-dimensional chart.
  3. Specify whether the data series are in columns or rows.
  4. Specify whether the first points in each series are labels or data.
  5. Click Create.
  6. Your chart will be generated ready for further editing if required.

Types of bar chart

There are eight types of bar chart available in Fireworkz, which can be further customised using the options available.

Bar

The first two buttons draw simple bar charts.

Stacked bar

The third button produces a stacked bar chart in which all data series within each category are combined into a single bar.

Percentage stacked bar

The fourth button gives a percentage stacked bar chart, where the data series within each category are expressed as percentages.

Pictograms

The buttons in the third row produce pictograms, in which the bars of the chart are made up out of pictures. Any Draw file or sprite file can be used as the basis of a pictogram.

The following tips apply for successful use of pictograms:

Error bars

This type of chart includes extension to the bars showing the potential error margin. Two consecutive data series are used to construct each bar; the first is used for the solid bar and the second for the error bar.

Cumulative bar chart

This option creates a bar chart where each new data point is added to the previous one, so the size of the bars will normally increase along the x-axis.

Line charts

Line charts are ideal for showing changes in a series of data over time.

When you choose the Line chart option from the Chart menu the Line chart dialogue box will appear.

  1. Click the image button representing the type of chart you want.
  2. Select the 3-D option if you want a three-dimensional ribbon chart.
  3. Specify whether the data series are in columns or rows.
  4. Specify whether the first points in each series are labels or data.
  5. Click Create.
  6. Your chart will be generated ready for further editing if required.

Types of line chart

There are eight line chart options available, consisting of four main types drawn with and without data points:

Simple line chart

This chart draws a line between the data points in each series.

Area chart

This chart draws a line between the data points, and then shades the area between this line and the axes of the chart. A further line is drawn from the x-axis to each data point.

Stacked area chart

This chart stacks data series, drawing a line between the points in each and shading the area between each line and the line below it.

Line chart with error bars

This chart draws a line with error bars extending from each data point. Each line in the chart requires two series of data; the first is used for the line data point and the second to place the error bar.

Pie charts

Pie charts are good for showing the relationships between a group of figures in proportion to the total.

Several different types of chart are available from the Pie chart dialogue box.

  1. Click the image button representing the type of pie chart labels you want.
  2. Click the segment layout image button you want, and set the distance for exploded segments if required.
  3. Click any options you require for custom starting points or direction.
  4. Click Create.
  5. Your pie chart will be generated and placed in the worksheet.

Labelling options

The four image buttons in the top row represent labelling options. Click the appropriate button to produce a pie with:

Exploding segments

The three image buttons in the next row represent explosion options. Exploding one or more segments of the pie can draw attention to that segment. Click the appropriate button for:

You should also specify the distance you want the segment(s) to be exploded. This is expressed as the percentage of the radius of the segment which falls outside the pie itself. Click the arrow buttons to increase or decrease the number, or type one in directly.

Start position

You can also specify whereabouts on the circle you want the pie to begin. Either click on one of the eight radio buttons, or type in a number in degrees (0 to 359).

Direction

The chart can proceed either clockwise (the default) or anti-clockwise. Click the option button if you want an anti-clockwise chart.

X-Y Scatter plots

Scatter plots display data as discrete points and with or without lines between them.

Chart tool button To create a scatter plot, select your data in the worksheet and click the Chart tool button on the toolbar. Choose X-Y from the Chart menu and a dialogue box will appear.

  1. Click the image button for the type of scatter plot you want.
  2. Specify whether the data series are in columns or rows.
  3. Specify how the data series are arranged.
    X, Y, Y means that you want to plot more than one y-series against a single x-series.
    X, Y, X, Y means that for each y-series you are supplying an x-series.
  4. Specify whether the first points in each series are labels or data.
  5. Click Create and your scatter plot will be drawn.

Types of scatter graph

There are nine types of scatter graph, based on three types of graph to which vertical error bars or vertical and horizontal error bars can be added.

Two sets of data are required for each point, to provide the x- and y-coordinates respectively. Vertical error bars are taken from the third set of data, and horizontal error bars from the fourth.

Line

A line is drawn from point to point. Note that Fireworkz does not automatically sort data for charts, and you should therefore sort the x-coordinates in ascending order or your line could travel both forwards and backwards across the chart.

Point

Each data point is represented by a blob at its x,y coordinate.

Line and point

Each data point is represented by a blob, and a line is drawn between the data points.

Overlays

Overlays place two y-axes on the same chart, one of which is placed at the left of the chart and one at the right. Each axis can be scaled differently and your data series can be plotted against either of the axes. To work with overlays:

  1. Chart tool button Choose Overlay from the menu which appears when you click the Chart tool button on the toolbar.
  2. Select the option you require from the Overlay dialogue box. Choose one of Bar-bar, Bar-line, Line-Line or Scatter-Scatter.
  3. Fireworkz automatically divides the data series into two and plots the first half on the left axis and the second half on the right axis.
  4. If a series appears on the wrong half of the chart, select it and change its status in the Overlay section of the Series dialogue box.

Editing your chart

Once you have created a chart, you can:

Most of these actions are the same as those which apply to pictures. See the earlier chapter, Pictures, for details of how to perform them.

Depending on the type of chart which you have created, you can also use specific chart commands to:

The following sections on each type of chart outline the editing possibilities for each type.

You cannot change the type of a chart once you have created it. For example, if you have made a bar chart you cannot turn it into a pie chart. If you decide that you have made the wrong kind of chart, you should simply delete the chart by selecting it and pressing the Delete key, select the data again, and create a new chart.

Updating chart data

The data in your chart is taken live from your spreadsheet. If this data changes, either because you have edited it or because of a recalculation, the chart will automatically be redrawn and updated. This happens until you turn the chart into a Draw file using Make constant.

‘Live’ charts vs. ‘dead’ charts

When you create a chart, you may have one of two intentions. You will probably want your chart to continue to reflect your data and any changes in it, to help you to analyse your data as you work. Or you may want your chart to present a snapshot of the data at that time. Fireworkz allows you to choose which of these options you prefer.

Accessing the chart menus

To edit charts, you need to use the chart menus and dialogue boxes. To access these, the chart must be selected for editing.

  1. Double-click within the chart frame, and you will see that a double red border appears around the chart area. The chart is now selected for editing.
  2. If you want to edit or change the appearance of a particular section of the chart (such as the y-axis, or a single data point), you need to select it as well.
    Data points
    For a single data point click Adjust (RISC OS) or Ctrl-click on the part of the chart required.
    Data series
    For a series, click on a point within the series.
  3. You will see a dotted line appear around the selected part of the chart. The selected area will also be described in the status line for example Series 1 or Series 2, point 1.
  4. Once you have selected the chart frame and the part of the chart you want to change, you will be able to access the chart menus. On RISC OS, the chart menus appear if you click Menu within the chart area. On Windows, the chart menu bar replaces the standard menu bar at the top of the Fireworkz window.
  5. You can choose the option you want and edit the chart.

Customising bar charts

There are several options for customising bar charts:

Bar positioning

You can customise the position of bars in the chart using the Chart dialogue box from the Edit menu accessed from the Chart menu.

Three-dimensional charts

All bar charts can be made three-dimensional by selecting the 3-D option when you create the chart or by setting the option button in the 3-D section of this dialogue box. They may be made two-dimensional by unsetting this option button.

You can also edit the pitch and roll of 3-D charts using the Chart dialogue box.

Editing axes

When Fireworkz draws your chart it will endeavour to produce the most acceptable divisions on the axes. However, you may want more or less precise numerical divisions, or a different type of tick mark.

To edit an axis:

  1. Double-click on the chart to select it. A double line will appear around the entire chart.
  2. Click Select (the left mouse button) on the axis you want to edit. A border will appear to show that it has been selected.
  3. Choose Axis from the Edit menu. The Axis dialogue box will appear.
  4. Edit the axis as necessary. Options available here include setting the numerical divisions on the axis, the position of the axis on the chart, grid lines and tick marks, and scaling. You can also opt to stack data series here, changing your bar or line chart into a stacked chart.
  5. When you have set all the options you require, click Apply. Your chart will be redrawn.

Using colour in charts

Charts are created using a default set of colours for each item. However, you may want to edit these, either for the whole chart or for individual items.

You may edit both the fill colours used for areas, bars and pies, and the line colours used for other objects.

To edit colour in charts:

  1. Double-click on the chart to select it. A double line will appear around the entire chart.
  2. Click Select (the left mouse button) on the chart element that you want to edit. If this is a data series, Select will select the whole data series for editing. If you want to edit a single data point, Ctrl-click Select on that point. A selection border will appear to show the extent of the area which will be changed. The status line will confirm which chart element is selected.
  3. Choose Fill from the Chart – Style sub-menu.
  4. The Fill colour dialogue box will appear, captioned with the name of the chart element that you are editing. Choose the colour you want, or select Automatic for Fireworkz to choose a colour for you.
  5. Select the fill style. Solid fills with a solid colour. Picture enables you to import a picture which you can choose from the pop-up menu. Further options maintain the imported picture's aspect ratio or allow it to be recoloured.
  6. Click Apply to confirm your changes. The chart will be updated.

Editing lines

Lines in charts appear in default colours and line styles. However you may edit these.

To edit lines:

  1. Double-click on the chart to select it. A double line will appear around the entire chart.
  2. Click Select (the left mouse button) on the chart element that you want to edit. If this is a data series, Select will select the whole data series for editing. If you want to edit a line associated with a data point, Ctrl-click Select on that point. A selection border will appear to show the extent of the area which will be changed. The status line will confirm which chart element is selected.
  3. Choose Line style from the Chart – Style sub-menu.
  4. The Line style dialogue box will appear. Choose a colour for the line or select Automatic for Fireworkz to choose the colour.
  5. Click on a button for a line style.
  6. Type in a width in points. If the width is set to zero, no line is displayed.
  7. Click Apply to confirm your changes.

Editing data series

You can edit aspects of each data series:

  1. Select the required data series.
  2. Choose Series from the Edit menu.
  3. Make your choices and click Apply.

Possible options are:

Positioning the chart

The margins around the edge of chart can be edited - these are the gaps between the edge of the chart itself and the border of its frame.

  1. Select the chart by double-clicking it and choose Margins from the Edit menu. The Chart margins dialogue box will appear.
  2. Enter the required margins in the current unit of measurement.
  3. Click Apply. Your chart will be repositioned as required.

Editing text in charts

You cannot type text directly into your charts. Any text must be selected in the worksheet when the chart is created, or added later using the Add command.

Arranging the legend

You can reposition the legend on the page, or change the way it is displayed:

  1. Select the chart by double-clicking it and choose Legend from the Edit menu.
  2. Select On to display the legend.
  3. Select Arrange horizontally to display the legend horizontally.
  4. Click Apply to confirm your changes.

If the chart does not have enough space to display the legend correctly, edit the margins as above to increase the space available.

Changing the style of text

You may change the style and colour of text directly in the chart. To do this:

  1. Select the text you want to change.
  2. Choose Text from the Style menu.
  3. The Text style dialogue box will appear.
  4. Choose the typeface you want from the list, and if required select the Bold and/or Italic option buttons.
  5. Enter a height for the text (i.e. its point size). If you do not specify a width, the natural width of the type will be used.
  6. Specify a colour for the text.
  7. Click Apply to confirm your changes.