EspressChart provides a number of ways to customize and configure the way data points are drawn and annotated on the chart, as well as the chart plot itself.
Many of the data display options are controlled through the data properties dialog. From this dialog you can control the size of bars/columns, set display options for null values, and specify options for data labels. To invoke the data properties dialog, select → or click the 
button on the toolbar. This will bring up the following dialog:
Data Properties Dialog
This data properties dialog contains the following options:
- Column width:
This specifies the ratio of the bar/column width with respect to the gap between successive bars in the chart. Each unit represents 1/10th of the space between data points. Therefore, entering
9would leave 10% of the space between data points blank, while10would eliminate all space between bars/columns. This option only pertains to two-dimensional bar, column, stack bar, stack column, high-low, HLCO, and Gantt charts. To control the column thickness in three-dimensional charts, you can use the thickness of shape slider in the navigation panel.- Show data for nulls:
This will connect lines when null data is present. For example, if you have three points and the value of point 1 is 4, point 2 is null, and point 3 is 6, then a line will be drawn from 4 to 6 for the three points. This property is only available for line charts or for other two-dimensional charts with lines. All other chart types will not plot data for nulls.
- Use dotted lines for nulls:
Instead of drawing a complete line through null values in the chart, you can use this option to specify a dotted line where the values are not present. Like the show data for nulls option, this property is only available for lines.
- Draw from end to end:
This option allows you to draw two-dimensional line and area charts across the entire plot area, rather than offsetting to the first and last data points on the chart.
- Show shadow on line:
This option specifies whether to show shading on two-dimensional lines. In order for shading to apply, the line must be thicker than one pixel.
- Show primary:
This will display data top labels for the primary values in the chart.
- Show stack section:
This will display individual labels for each stack section for stack bar, stack column, and stack area charts.
- Negative Label Color:
This will display the top labels with a value smaller than that of the origin in a different color that can be selected using the button after enabling the feature.
Chart with Colored Negative Top Labels
- Show secondary:
This will display data top labels for the secondary values in the chart.
- Top label position
This allows you to specify where the data top labels should be drawn. They are drawn above data points by default if they are positive and below data points if they are negative. Use the other options here, you can force the data points to always draw to the positive or negative side of the data.
- Label Alignment:
This option allows you to set the alignment for the data top labels. You can draw them at the top, bottom, or middle of the data points. In addition, you can select to draw the label inside the data point at the top or bottom. An additional option stack charts offers you to set the alignment for stack section labels.
For charts displaying date or time data on the category axis, EspressChart provides a unique feature allowing users to perform date/time based zooming. Using this feature, you can group the category elements into user-defined intervals and aggregate the points in each group. You can also filter the data by specifying upper and lower bounds for the results.
For example, suppose your data contains daily sales volume for the past two years. Using zooming you could aggregate the data to look at average volume per month, quarter, or year. Using the upper and lower bounds you could narrow the range to look at weekly sales volume within a specific quarter.
Zooming is available for all chart types except scatter, surface, box, dial, polar, radar, bubble, and Gantt.
When you create a new chart with date, time, or timestamp data in the category axis, you will be automatically prompted to specify zooming options. You can manually invoke the zooming option dialog by selecting → .
When you first select to add zooming a dialog will appear, prompting you to specify aggregation options for the grouped data points.
Aggregation Options Dialog
In this dialog you can specify the aggregation either sum, minimum, maximum, average, or count, as well as the maximum and minimum scale increments that can be used when zooming the data. After you have specified the options that you want, click and a new dialog will appear allowing you to specify additional zooming options.
Zoom Options Dialog
This dialog allows you to specify a lower and upper bound for the data, as well as the interval by which you would like to group the data. The scale specified here must be within the maximum and minimum scale specified in the aggregation options dialog.
This dialog also allows you to preserve a linear scale for the chart. By setting the Linear option to true, the chart will always display points for the grouped intervals, even if there is no data associated with a particular group. For example, say again that you are measuring sales volume over a three month period - April May and June. If the input data has no records for May and you set the Linear option to true, a point will be drawn for May with a value of zero. If you set the "Linear" option to false, the data point for April will be immediately followed by June.
You can disable/enable zooming, as well as the lower and upper bound restrictions by using the checkboxes at the bottom of the dialog. Once you have finished specifying all the options, click and the zooming will be applied to the chart.
When deploying charts using Chart Viewer, end users can perform dynamic zooming. To perform a time-series zoom in the Chart Viewer, Ctrl+Click on a point on the chart and drag it to another point in the chart. This will automatically zoom in based on the lower and upper bounds selected using the mouse. The aggregation is performed according to the options that was set at design time. You can undo the zoom by Ctrl+Right-Click.
The scale internal is automatically chosen, depending on the data and the bounds chosen (as long as minimum 2 data points can be shown). The scale interval can also be changed in the Chart Viewer by pressing Alt+Z. This will bring up a dialog allowing the user to change the zoom settings.
EspressChart allows you to change the order of the category and series elements. To modify the ordering, select → or click the 
button on the toolbar. This will bring up the following dialog:
Data Ordering Dialog
There is an Order By list which contains the category element, the series element, and an option marked VALUES. You have the following options for the category and series elements:
DataSource Order: | Turns the ordering off. The categories/series order will depend on the data source only and will not be altered by the EspressChart at all. |
Ascending: | This will arrange the categories/series elements in ascending order. For example, if the category elements are strings, they will be arranged alphabetically. |
Descending: | This will arrange the categories/series elements in descending order. |
Customize: | Allows you to customize the categories/series order. To customize the order, select an item from the list of Categories/Series items and then move it upwards or downwards in the list by clicking on the or button (the buttons are inactive until if you select the Customize option). |
You can also sort the category elements based on their corresponding values. To do this, select the VALUES option in the data ordering dialog.
Value Data Ordering Dialog
If you choose the VALUES option, the dialog changes. From this dialog you can specify to sort the category elements based on their corresponding values in the value, or secondary value axis. You can also specify whether to sort them in ascending or descending order. This resulting sort by value chart is called a Pareto chart, and is often used in process control applications.
Pareto Chart
Please note that any sorting set will be re-applied if the chart is refreshed and/or if the data changes.
Sometimes, you want to plot only a few highest or lowest values. To do that, you can use the Top/Bottom N function.
To enable this feature, choose → , or click the button on the toolbar.
If the chart doesn't have any data series, the Ordering dialog will show the Limit Number Of DataPoints option.
This option can be enabled only if you order the chart by the categories or by the values in ascending or descending order. If you have such a chart, you can enable this function by selecting the Show first option. Then you can specify the maximum number of items that will be shown in the chart. If the data source returns more items than you specify in this option, excessive items will not be shown in the chart as if they didn't exist.
Histograms are a useful analysis tool, by allowing you to track the frequency that events occur, or the way that a set of data falls into specific ranges. EspressChart allows you to plot histograms based on the category elements in a chart. You can plot histograms for all category data types except time-based data (date, time, or timestamp).
Histograms are calculated by counting data points or instances of each category element. For numeric categories, you can further specify upper and lower bounds, as well as a scale to create ranges for the frequency counts.
To create a histogram, select → . A dialog will appear allowing you to select a histogram plot.
Select Histogram Dialog
When you select the Draw Histogram option another dialog will appear allowing you to specify options for the histogram plot. From this dialog you can select a lower or upper bound for that data being plotted. When you place bound restrictions, then the histogram will not count data that falls outside of the range specified by the upper and lower bounds. Generally it only makes sense to place bound restrictions on numeric category elements.
Histogram Options Dialog
For numeric category elements, you can also specify a scale in order to provide value ranges or groups in which to compute the frequency count. To specify a scale, select the Enable Scale option. This will bring up a new dialog allowing you to specify the scale.
Histogram Scale Options
Here you can specify the number of units to be in each scale step. You can also specify whether to preserve a linear scale. This will draw a range on the category axis, even if there are no corresponding data points. For example, if the frequency count is zero between 20 and 30 then the “30” element will still appear on the category axis with a count of zero. However if linear scale is turned off the “30” element will not be drawn in the chart.
The plot area is the plane on which the data points are drawn for two-dimensional charts. You can customize the appearance of the plot area by selecting → . Assuming the current chart is a two-dimensional chart the following dialog will appear.
Plot Area Dialog
This dialog allows you to draw a border around the plot area, or fill it to provide a background color. If you fill the area, you can also specify certain three-dimensional effects either raising, lowering, or drawing a shadow.
On this dialog, you can also set up gradient background for the plot area. The gradient settings are the same as in the Rendering options described in the Section 6.1.3 - Format Menu.
You can control and modify the display of the chart legend by selecting → , by clicking on the 
button on the toolbar, or by selecting Legend properties from legend pop-up menu (which pops up when you right-click on the legend). This will bring up the following dialog, allowing you to customize the legend properties.
Format Legend Dialog
The dialog contains the following options:
Display: | These options allow you to turn on or off the legend border, and background. This also allows you to display the point symbols instead of lines or blocks in the legend. |
Effect: | This allows you to add a three-dimensional effect to the legend. You can raise it, lower it, or draw a shadow. In addition to 3D effects, you can also display the legend with cut corners. |
Layout: | This allows you to change the legend from vertical, horizontal, square, or fixed column layout. |
Gradient: | Allows you to configure gradient for the legend background. The gradient settings are the same as in the Rendering options described in the Section 6.1.3 - Format Menu. |
Other: | This allows you to choose whether or not to display the legend, or to draw the legend in reverse order. You can set the fixed number of columns in legend in the Number of columns field. This field will be active only if you choose the Fixed columns layout option in the Layout section. You can also change the size of the symbols in the legend. |
In addition, you can remove specific category/series elements from the legend, by clicking the button. This will bring up a list of the legend items, where you can select which elements you would like to hide.
EspressChart renders three-dimensional charts in true 3D allowing light source modification, panning, zooming, and rotation. However, 3D rendering can be very memory and CPU intensive. When charts have a lot of data points (like 3D scatter and surface charts) it's possible to run out of memory when generating the chart. To solve this problem, a rendering approximation feature is provided. Using this algorithm the chart is not rendered perfectly, but it's usually acceptable when a lot of points have to be shown.
By default, approximation is turned on at a threshold value of 100 points. What this means, is that if a 3D chart has more than 100 data points that approximation will be used. You can turn off the approximation feature, or change the threshold value by selecting → . This will bring up the following dialog.
3D Display Options Dialog
The two options for 3D approximation allow you to turn on/off the approximation, and to set the threshold value. The other option in this dialog allow you to draw the series in-line (this is the same as the option in the navigation panel).
For column, bar, stack column, stack bar and HLCO charts, EspressChart allows you to configure a border around the columns. To set the border option, select → . This will bring up a dialog allowing you to set border options.
IData Border Dialog
The first option allows you to turn on/off the data border. The second option allows you to set a black border for any white areas in the chart. Please note that the border is black only if the first option is unchecked and will only appear around white areas in the chart. The third and fourth options allows you to set the border thickness, and the border color. If you click the button a dialog will appear allowing you to select or enter a new color.
EspressChart allows you to aggregate the data if there is more than one data point associated with a given category (and its series and/or stack, if a series and/or stack is present). This allows for a broader look at the data rather than just a single data point (out of many).
To aggregate the data, select → . A dialog will appear allowing you to enable aggregation.
Select Aggregation Dialog
When you select , a second dialog box appears asking for the type of aggregation to be applied. You can choose from maximum, minimum, average, sum and count for the aggregates. You can specify a primary aggregate (aggregate applied to the column mapped to the primary axis) as well a secondary aggregate (aggregate applied to the column mapped to the secondary axis), if a secondary axis exists.
Aggregate Options Dialog