Histogram series

The histogram series is a distribution series, displaying the count of the occurrences of values within a given range. That count is used to determine the height of a bar that is drawn for each bin, or data subrange. The data range of each bin is from the minimum numeric value of the bin, up to, but not including, the maximum data value of the bin.  If, for example, four values in the data series occur within a given bin (i.e. four values are greater than or equal to the minimum and less than the maximum range of a given axis step), then the value of the bar that is drawn for that bin will be 4.

The bins - the bin count and range min and max of each bin - are established and controlled by the Grid's X axis. Should you wish to override the Auto Adjusting feature of the Grid, which automatically adjusts the axis range and axis step size, and thus the bin count and bin range of the histogram series, you must use the Grid Inspector. For example, if the range of your data is from 1 to 10, the grid will adjust to provide ten bins from 1 to 11 (to 11 because the value 10 is stored in a bin whose range is from 10 to 11). Should you wish to change this to only five bins, then you would edit the Step of the X Axis and make it 2 instead of 1. Please note, the size of each bin must be the same as all of the other bins. So in our example, if you changed the Axis step to be 3, the range of 1 to 11 cannot be divided into bins that are each of size 3 (the resulting bins would be from 1 to 4, 4 to 7, 7 to 10, and 10 to 11). For this example, valid step sizes are ... .5, 1.0, 2.0, 2.5, 3.333, 5, 10. If you change the Axis range or step such that each bin is not the same size, your results may appear to be erroneous.

Histogram series accept dragged colors to set the fill color and to set the line color. Histogram series also accept dragged image files, displaying the image on the face of each bar. All other attributes of a Histogram series may be changed through the Histogram Series Inspector.

To produce Histogram series with a 3D Effect, change the Grid to have a 3D Effect in the Grid Inspector.  See the Grid help file for more information.

To produce horizontally oriented Histogram series, change the orientation of the Grid to horizontal in the Grid Inspector. See the Grid help file for more information.




Histogram Series Inspector

When a Histogram series is selected in the chart, the Inspector displays the controls that are used to set its attributes.  The Histogram Inspector contains a tab view with four tabs: Style, Labels, Shared, and Trends.  The contents of each of those tabs is addressed separately below.

Style Tab

The attributes set with controls found in the tab labeled ÒStyleÓ apply only to the currently selected Histogram series. Changing the values of these attributes does not affect any of the other Histogram series in the chart unless they are also selected.

¥ Line Width and Color
The Line Width slider and the color well set the width and color of the lines outlining the bars in a Histogram series.

¥ Gradient Fill
Histogram series can be filled with a solid color or with a two-color gradient.

 

Start Color - Sets the start color of the gradient fill (color at the bottom of the Bar).

End Color - Sets the end color of the gradient fill (the color at the top of the Bar).

Color Switch - The swap button exchanges the gradient start color with the gradient end color.

¥ Image
A Histogram series can contain an image. The image is set by dragging an image file into a Histogram series or by using the Set Image button on the Inspector.

 

Image Only - Turns off the drawing of the Bar, and only shows the image. This button has no effect on drawing if there is no image for the series.

Stack Image - Stacks the image in the histogram bar. The size of the image is determined by the major step value of the Y Axis the series is associated with. This button has no effect on drawing when there is no image for the series.

Set Image - Sets the image for the Histogram series through an open panel.

Clear Image - Clears any image currently in the series.

¥ Display series on Y1 / Y2 Axis
Associates the series with either the Y1 or Y2 axis (the axis must be active in order to associate a series to it). The data range of the associated axis will determine how the series is drawn.

Labels Tab
 
The contents of this tab are used to control how to label the histogram bars in the series and where to position the labels.

¥ Labels (on/off)
A switch titled ÒLabelsÓ at the top of the tab view panel will enable or disable the series labels for the selected series.

¥ Label Content
The content of the data labels is set to:
Data - numeric labels
Text - textual labels
Text and Data - both textual and numeric values in the labels

The textual labels specify the data range that the given Histogram bar represents. The numeric labels are the count of data values in the data range that is represented by that Histogram bar. When choosing the percent option, data labels are shown as a percentage of the whole series.

¥ Label Position
Label Positioning options are:
Center - In the center of the Bar face
Above - above the Bar face
Below - below the Bar face
Left - to the left center of the Bar face
Right - to the right center of the Bar face
Series labels can be double-clicked to deep-select them, then dragged freely across the chart. When this is done, the label position is set to ÒCustomÓ.

¥ Label Color
The Label Color color well sets the display color of series labels.

¥ Label Rotation
The Rotation controls set the rotation of all of the series labels.
 

Shared Tab

The shared attributes are common to all Histogram series in the chart. Changing the value for the selected Histogram series changes the value for all other Histogram series in the chart.

¥ Top Shading
If the chart is using a 3D Effect Grid, then Histogram series also draw with a 3D effect. The Top Shading slider sets the shading value used to draw the top of a 3D bar. The Side Shading value is the same for all Histogram series in a chart.

¥ Side Shading
If the chart is using a 3D Effect Grid, then Histogram series also draw with a 3D effect. The Side Shading slider sets the shading value used to draw the side of a 3D bar. The Side Shading value is the same for all Histogram series in a chart.

Trends Tab

The contents of the Trends tab is used to add trend lines to the selected series.  Any number of trends can be added, each with their own set of attributes, but all associated with the data of the selected series.

¥ Add Trend / Delete Trend
At the bottom of the trends tab are two buttons used to add and delete trends.  Initially only the Add Trend button is enabled.  When the Add Trend button is clicked, a single trend is added.  For each added trend, an item is added to the popup button that is toward the top of the Trends tab.  This popup button displays the trend label for each of the trends that have been added, and is used to select a trend.

To delete a trend, select the trend from the list of trends in the popup button toward the top of the Trends tab, then click the Delete Trend button.

¥ Type
The mathematical model for a given trend can be set using the Type popup button.  If the trend type has a modifier value, the control for that value is displayed to the right of the trend type popup.  For example, the Polynomial trend type has an Order modifier, and the Moving Average trend type has a Period modifier.

¥ Active
The Active switch is used to activate and deactivate a trend.  When a trend is deactivated, it is not displayed in the chart and is not referenced in the chart legend.

¥ Show Entry in Legend
This switch is used to include or exclude an entry that represents the trend from the chart legend. 

¥ Draw in front of series
Allows you to set the trend to draw in front of or in back of the associated seris. 

¥ Label
The default label for a trend is Ò<Series Name>(Trend #)Ó.  This label can be modified with the Label textfield.  This label is used to identify the trend in the chart legend, and is also used to identify the trend in the trends popup toward the top of the Trends tab.  

¥ Line Width and Color
Used to set the width and color of the trend line. 

¥ Equation Annotation
You can drag a textual annotation from this icon well that will display the mathematical equation computed for the associated trend.