A raster grid can be classified in a number of ways in MapInfo Pro Advanced including classifying different bands and fields with in an MRR file.
The most common way is to classify a grid based on a range of values. A single value class can then be assigned to the range in either numeric or character form. In the example below, the grid represents cell phone network signal strength. The values could be numeric, e.g. 0 for No Coverage and 1 or Good Coverage, or it be classed as character stating the string “No Coverage” or “Good Coverage”.
Go to Raster > Raster Operations.
Input File > Set to the Raster that requires classification.
Output Raster type > Set to Classified (this will allow character entry instead of numeric).
Class Interval Type > Set to Discrete (Discrete allows values to be changed in intervals without automatically changing values in the other intervals).
Derive Class Colours From > Set to desired colour table.
The example grid has values from -170 to +40, these values represent the estimated signal strength. -101 and above is Good Signal, -100 and below is No Coverage. Select and use Ctrl to select all but two intervals and then click Delete Row.
Enter the value sets -170 | -101 and -101 | 50. Change the colour of each interval by clicking on the colour box and selecting a new colour to provide contrast for the two intervals.
File Name > Set to required file name.
Click Process.
The new classified grid will be ready to open in a new Map Window.
See Attachment
In this case the coverage map has been clipped.
Raster > Raster Operations > Clip. An administrative boundary has been used.
The percentage area with "Good Coverage" and "No Coverage" can be quickly determined using grid statistics.
Raster > Statistics.