Histogram Charts

A histogram is a chart that takes a collection of raw data values and plots the frequency distribution. It is frequently used with grouped data, which is generated by measuring a collection of raw data and plotting the number of data values that fall within defined intervals. Note that raw values are not used to generate data for a histogram, but are used to generate a frequency instead. While showing similarities to bar charts, it is important to note that histograms are used with quantitative variables whereas bar charts are commonly used with qualitative variables.

A histogram is beneficial for pinpointing prominent features of the distribution of data for a quantitative variable. The important features for a quantitative variable include the following:

· It reveals the typical average value.

· The data yields a general shape. The data values can be distributed symmetrically around the middle or they can be skewed.

· If there are distant values from the group of data it shows them as outlier values.

· The data values can be near or far to the typical value.

· The distribution may result in a single peak or multiple peaks and valleys.

Note: The interval values represent the frequency of data elements. There are many different techniques used for displaying frequency. Frequency is commonly displayed in the shape of a polygon, column, or bar graph.

To set the chart type to Histogram at design time

· Expand the ChartGroups node in the .NET Properties window. In the right pane of the editor, set the ChartType property to Histogram.

· Another alternate method is to expand the ChartGroups node in the .NET Properties window. Open the ChartGroups Collection Editor by clicking the ellipsis button. In the right pane of the editor, set the ChartType property of the appropriate ChartGroup to Histogram.

Histogram Chart Programming Considerations

Types of Histogram Graphs