*MapCalc
**Cross-Reference
of Analysis Operations for **Spatial
Analyst *

**Organization
of MapCalc analytical operations**

All

·
**Reclassifying
maps**—operations CLUMP, CONFIGURE, RENUMBER, SIZE, and SLICE

·
**Overlaying maps**—operations
COMPOSITE, COMPUTE, CALCULATE, COVER, CROSSTAB and INTERSECT

·
**Measuring
distance and connectivity**—operations DRAIN, RADIATE,

·
**Characterizing
neighborhoods**—operations INTERPOLATE, ORIENT, PROFILE,
SCAN and SLOPE

·
**Statistical
relationships**—operations ANALYZE, CLUSTER, COMPARE,
CORRELATE, REGRESS and RELATE.

This organizational scheme is based on the user's perspective of
map input and output contents—what the map(s) look like going in, and coming
out.

** RECLASSIFYING** operations
assign new values to each map category on an existing map layer. Regardless whether you RENUMBER, SLICE, SIZE,
CLUMP or CONFIGURE, the resulting map will have the same "boundaries"
(spatial arrangement) as the input map.
The new values might be ones you directly assigned (RENUMBER), or the
ones the computer automatically assigns (SLICE), or ones based on the area of
each category (SIZE), or ones indicating the shape of the individual features
(CONFIGURE). If the same value is
assigned to two adjacent categories, the boundary disappears. In CLUMP, if a feature is composed of several
discrete groupings, each will each get a different value and the individual
boundaries will be distinct. However, in
all RECLASSIFYING operations, the similarities in the spatial arrangement of
features on the input and output maps are readily apparent—just a different set
numbers.

** OVERLAYING**
operations are radically different as they assign new values based on the
independent values on two or more maps.
Commands COMPUTE/CALCULATE (with map variables), COVER and INTERSECT
overlay maps on a "point-by-point" (cell-by-cell) basis. In each instance, an entirely different
looking map is generated as output.
"Region-wide" overlay, on the other hand, results in a map
with similar spatial arrangement of features as those on the
"template" map. The map
categories on the template map identify the locations (cells) whose values from
the "data map" are summarized.
For example, the command “

** DISTANCE MEASUREMENT**
operations assign values as a function of simple or weighted connections among
locations. In each instance, a map of
"starter" locations is converted into a map characterizing their
connectivity to their surroundings. The
connections can be "simple," or "weighted" by intervening
conditions. The SPREAD (proximity), and

** NEIGHBORHOOD**
operations assign values that summarize conditions within the vicinity of map
locations (i.e., "roving window").
In the case of SLOPE, ORIENT and PROFILE commands, the summary implies a
characteristic of a surface, or gradient map.
In the case of INTERPOLATE or SCAN, the summary is a mathematical or
statistical summary of the values within the neighborhood.

** STATISTICAL**
operations assign values as a function of the statistical relationships among
maps. In the case of ANALYZE descriptive
statistics are reported for a stack of map layers. In the case of CORRELATE and REGRESS the
spatial relationship among maps is reported in tabular and equation form. CLUSTER
and RELATE generate a new map that shows the similarity among and within maps,
respectively. COMPARE produces maps and
tabular comparisons between maps.

**Spatial Analyst**** **is a raster map analysis toolbox that is part of the
Arc

**RECLASSIFY OPERATIONS**: New values are assigned as a function of the initial value,
size, shape, or contiguity of each map category on a map.

·
**CLUMP** -- MapCalc operation that assigns new values to contiguous groups
of cells within each map category.
Related Spatial Analyst tools are—

__Generalization
Toolset__*: Contiguity tools:***Region Group ****(plus ****Nibble, Majority Filter )**

·
**COMPUTE** (one map) -- MapCalc operation that assigns new values to each map
location as the mathematical or statistical function of the existing value.
Related GRID commands are

__General Math Toolset__*, Basic
Arithmetic tools:** ***Plus, Minus****, Times, Divide Power**

__General Math Toolset__*, Power tools: ***Square, Square Root**

__General Math Toolset__*, Exponential and
Logarithmic tools: ***Exp, Exp2, Exp10, Ln,
Log2, Log10**

__Trigonometric Math Toolset__*: ***Cos, ****Sin, Tan, ACos, ASin,
ATan, ATan2, CosH, SinH, TanH, ACosH,
ASinH, ATanH**

__Map Algebra Toolset__*: ***Raster Calculator**

·
**CONFIGURE** -- MapCalc operation that assigns new values characterizing the
shape of the area associated with each category. Related Spatial Analyst tools
are—

**None**,
but shape statistics can be derived from ArcGIS tables through user-defined
Python scripts.

·
**RENUMBER** -- MapCalc operation that assigns new values to the categories on
a map. Related GRID commands are

__Reclass____ Toolset__*, Reclassification tools: ***Reclass**

·
**SIZE** -- MapCalc operation that assigns new values according to the
size of the area associated with each map category. Related Spatial Analyst tools are—

__Zonal Toolset__*, Zonal Geometry tools: ***Zonal Geometry **

·
**SLICE** -- MapCalc operation that assigns new values by dividing the range
of values on a map into specified intervals (contouring). Related Spatial Analyst tools are—

__Reclass____ Toolset__*, Reclassification tools: ***Slice
**

**OVERLAY OPERATIONS**: New values are assigned as a function of the independent values
associated with each map location or categories on two or more existing maps.

·
**COMPOSITE** -- MapCalc operation that creates a map summarizing values from
one map that coincide with the categories of another. Related Spatial Analyst tools are—

__Zonal Toolset__*, Zonal Statistics tools: ***Zonal Statistics **(*Sum*, *Mean*, *STD*, *Median*, *Minimum*, *Maximum*, *Range*, *Majority*, *Minority*, and *Variety*)

·
**COMPUTE** (two or more maps) -- MapCalc operation that creates a map as the
mathematical or statistical function of two or more maps. Related Spatial Analyst tools are—

__General Math Toolset__*, Basic
Arithmetic tools:** ***Plus, Minus****, Times, Divide Power**

__General Math Toolset__*, Power tools: ***Square, Square Root**

__General Math Toolset__*, Exponential and
Logarithmic tools: ***Exp, Exp2, Exp10, Ln,
Log2, Log10**

__Trigonometric Math Toolset__*: ***Cos, ****Sin, Tan, ACos, ASin,
ATan, ATan2, CosH, SinH, TanH, ACosH,
ASinH, ATanH**

__Map Algebra Toolset__*: ***Raster Calculator**

·
**COVER** -- MapCalc operation that creates a new map where non-zero values
of the top map replace the values on the previous (bottom) map, or stack of
maps. Related Spatial Analyst tools are—

**None**,
but shape statistics can be derived from ArcGIS tables through user-defined
Python scripts.

·
**INTERSECT** -- MapCalc operation that creates a map by assigning new values
to pair wise combinations of the values on two maps. Related Spatial Analyst tools are—

__Local Toolset__*, Combinatorial tool: ***Combine**

**DISTANCE OPERATIONS**: New values are assigned as a function of the simple or effective
distance, optimal movement, narrowness, or visual connectivity among map
locations.

·
**DRAIN** -- MapCalc operation that creates a map indicating the number of
steepest paths (optimal path density) from a set of locations along a
surface. Related Spatial Analyst tools
are—

__Hydrology Toolset__*, Flow Density tools: ***Flow Accumulation ****(plus Flow Length, Flow
Direction, Sink, Fill,
Watershed, Basin, Focal Flow)**

·
**RADIATE** -- MapCalc operation that creates a map indicating areas that are
visible from specified locations.
Related Spatial Analyst tools are—

__Surface Toolset__*, Visual Connectivity
tools: ***Viewshed ****(plus Observer Points)**

·
**SPAN** -- MapCalc operation that creates a map indicating the narrowness
within areas associated with each category of a map. Related Spatial Analyst tools are—

**None**.

·
**SPREAD** -- MapCalc operation that creates a map indicating the shortest
effective distance from specified cells to all other locations. Related Spatial Analyst tools are—

__Distance Toolset__*, Euclidean Distance
tools: ***Euclidean Distance ****(plus Euclidean Direction, Euclidean Allocation) **

__Distance Toolset__*, Effective Distance
tools: ***Cost Distance ****(plus ****Cost Allocation, Cost Back Link)**

·
**STREAM** -- MapCalc operation that creates a map identifying the steepest
downhill route along a surface (optimal path).
Related Spatial Analyst tools are—

__Hydrology Toolset__*, Surface Configuration
tools: ***Flow Length ****(plus Flow Direction, Sink,
Fill, Watershed, Basin, Focal Flow)**

**NEIGHBORHOOD OPERATIONS**: New values are assigned as a function of the independent values
within a specified distance and direction around each map location.

·
**INTERPOLATE** -- MapCalc operation that creates a continuous surface from point
data. Related Spatial Analyst tools are—

__Interpolation
Toolset__*: ***IDW**** (plus Kriging, Spline,
Spline with Barriers, Natural Neighbor, Trend)**

·
**ORIENT** -- MapCalc operation that creates a map indicating aspect along a
continuous surface. Related Spatial
Analyst tools are—

__Surface
Toolset__*, Surface Configuration
tools: ***Aspect ****(plus Curvature)**

·
**PROFILE** -- MapCalc operation that creates a map indicating the
cross-sectional profile along a continuous surface. Related Spatial Analyst tools are—

**None**.

·
**SCAN** -- MapCalc operation that creates a map summarizing the values
that occur within the vicinity of each cell.
Related Spatial Analyst tools are—

__Neighborhood
Toolset__*, Focal (roving window)
tools: ***Focal Statistics **(*Sum*, *Mean*, *STD*, *Median*,
*Minimum*, *Maximum*, *Range*, *Majority*, *Minority*, and *Variety*)

·
**SLOPE** -- MapCalc operation that creates a map indicating the slope (1st
derivative) along a continuous surface.
Related Spatial Analyst tools are—

__Surface
Toolset__*, Surface Configuration
tools: ***Slope**

**STATISTICAL OPERATION**: New values and statistical summaries are assigned as a function
of the numerical relationships among maps.

·
**ANALYZE** -- MapCalc operation that creates a map of the simple or weighted
average, standard deviation, coefficient of variation and several other
descriptive statistics for two or more maps (map stack). Related Spatial Analyst tools are—

__Local Toolset__*, Cell Statistics tools: ***Cell Statistics **(*Sum*, *Mean*, *STD*, *Median*,
*Minimum*, *Maximum*, *Range*, *Majority*, *Minority*, and *Variety*)

·
**CLUSTER** -- MapCalc operation that creates a map that identifies areas
with similar data patterns (characteristics) using a stack of input map
layers. Related Spatial Analyst tools
are—

*Multivariate
Toolset, Classification tools: ***Iso**** Cluster Unsupervised
Classification**** **

·
**COMPARE** -- MapCalc operation that generates a summary table of various
comparison statistics between two maps.
Related Spatial Analyst tools are—

**None**.
Comparative statistics can be derived by evaluating index equations
using the Raster Calculator or a Python script.

·
**CORRELATE** -- MapCalc operation that generates a correlation matrix from a
stack of maps. Related Spatial Analyst
tools are—

**None**. Correlation can be derived using a Python script. Also, the Band Collect tool in the Multivariate
toolset provides correlation and covariance summaries.

·
**REGRESS** -- MapCalc operation performs a linear regression analysis by
using the "least squares" method to fit a line through a set of data
points in multiple maps (map stack) and outputs the regression coefficients of
the prediction model. Related Spatial
Analyst tools are—

**None**. Correlation can be derived using a Python script.

·
**RELATE** -- MapCalc operation that creates a map that quantifies the
similarity of each location on a map to an evaluation data pattern, or set of
comparison values. Related Spatial
Analyst tools are—

**None**.

*(updated
April 2012)*