STEMgis Data Types

There are a number of different types listed below:

• Char - used for text descriptions, names or textual classifications (limit is 255 characters)
• Integer - used for counts, sales or other attributes that use whole number (i.e. -2,147,483,648 to 2,147,483,647)
• Real - used for single precision decimal numbers (i.e. stores numbers from 3.402823E38 to 1.401298E–45 for negative values and from 1.401298E–45 to 3.402823E38 for positive values.
• Double - used for double precision decimal numbers (i.e. stores numbers from 1.79769313486231E308 to 4.94065645841247E–324 for negative values and from 1.79769313486231E308 to 4.94065645841247E–324 for positive values.
• Gridc - used for loading image attributes. The images must be byte format bitmap images formatted either as windows bitmap (BMP), portable network graphics (PNG), or as JPEG format.
• Gridr - used for loading other raster data as attributes. The images must be in STEMgis Image Processing System (SIPS) format, which enables multi-band data of byte, integer and real binary type.
• Movie - used for loading movie attributes. The images must be formatted as AVI movie files.
• Binary - used to load binary files such as Word documents or Excel spreadsheets associated with spatial features. The user of the STEM database must have the appropriate program to view the file type loaded.
• Array - this data type is used when two attributes are inextricably linked and need to be plotted one versus the other. The data types are variant, i.e. they can be char, integer, real or double. An example might include a cumulative frequency graph where one attribute is plotted against percentage. Another example might be a spectral curve where the radiance or reflectance is plotted against wavelength. In these cases the 'percentage' and 'wavelength' data types should be defined as an ARRAY data type while the related attribute is defined using one of the options above.