GIS Analysis Functions Objectives To be able to

GIS Analysis Functions

Objectives • To be able to explain what the following GIS analysis functions are: – Transformations – Conflation – Edge Matching – Editing Functions – Query Functions – Overlay Operations – Neighborhood Operations – Connectivity Functions

Transformations • Format Transformations - sometimes topology must be built • Geometric Transformations - registration to a common coordinate system (rubber sheeting or warping) • Between Geometric Projects - i. e. Latitude/Longitude to PLSS

Conflation • procedure of reconciling the positions of corresponding features in different layers (i. e. if two forests layers are off - conflation fixes)

Edge Matching • adjusts the position features that extend across map boundaries ("postagestamping" maps together and resolving the differences in features along their edges. . . )

Editing Functions • slivers or splinters • line snapping • over- or undershoots

Query Functions • retrieve records in the attribute database according to the conditions specified by the operator

Overlay Operations • arithmetic & logical overlay operations • arithmetic - addition, subtraction, division, multiplication • logical - where a specified set of conditions occur (or doesn't occur) together

Neighborhood Operations • evaluate the characteristics of the area surrounding a specified location

Other Analyses

Connectivity Functions • use functions that accumulate values over the area being traversed

Conclusion • GIS analysis functions use the spatial and non-spatial attribute data to answer questions about real-world • Spatial analysis functions that distinguishes GIS from other information systems