Histogram Analysis

Histograms are a familiar method for displaying numerical information and have the added benefit of providing a visual representation of the data in which:

• Total data range for a particular element

• Modes can be easily recognized

• The range of greatest abundance of values can be estimated rapidly

• The general form of the density distribution of data is apparent

• The data can be coloured using statistical calculations of the selected lines in the database

They are also useful for distinguishing between background and anomalous values (i.e. quality control), or for recognizing a bimodal data distribution (i.e. interpretation). In many cases, the logarithmic transform of raw data is important because it provides a normal form to the density distribution; in which case, the data is said to be log-normal.

The Geochemistry system provides an interactive histogram analysis tool that displays the selected channel, channel statistics, histogram width, current cursor position and corresponding data value and percentile values. The tool is a dynamic dialog box that updates data values whenever you make a change to a corresponding value in the database.

In addition to providing a quality control tool for analyzing your data, the histogram tool enables you to create classified symbol plots with symbol legends for your maps.

Once the histogram tool has been created, it is stored as Tools (Geostats/ Geochemistry) in the Project Explorer (on the Tools tab). The Tools (Geostats/ Geochemistry) can be hidden/displayed as necessary (right-click on the tool in the Project Explorer and select ‘Hide’ or ‘Show’ from the popup menu). TheTools (Geostats/ Geochemistry) are saved in the project when you close Oasis montaj and will be available automatically, with the same settings, the next time the project is opened.

The Histogram tool can be docked either at the top, bottom, or sides of the current project window, and it can be resized up to the full size of the screen.