SPACE

Installing SPACE

1. Save the SPACE Zip file in the location of your choice.
2. Unzip the file by selecting it and choosing “Extract All” from the “File” menu.
3. Double click on the “setup.exe” file to install the SPACE extension. Follow the steps provided during the installation.
4. When the installation is complete, add the extension in ArcMap.
5. Add your data.
6. Use the SPACE toolbar to analyze your data.

Adding the SPACE extension to ArcGIS

1. Select “Extensions” from the “Tools” menu.
2. Select the checkbox next to “SPACE”, and click “Close”.

Adding the SPACE toolbar to ArcGIS

1. Select “Toolbars” from the “View” menu.
2. Select “SPACE”. A check mark will appear next to “SPACE” in the menu.

Study Area (Activity Space)

SPACE’s Activity Space function identifies the Study Area of your cases. It provides a standardized area for conducting and comparing analyses. Activity Space provides two options for creating your study area..

Exact extent of the points - Bounds the study area to the outer-most cases. This option creates a rectangle that touches your outer cases.

Extent of the points plus 10% - Creates a study area that is 10% larger than the exact extent. This also helps you avoid edge effect errors by including important geographic influences outside the extent of your cases.

Calculating Activity Space with SPACE

1. From the SPACE toolbar, click the ”Activity Space” button.
2. Select the layer for which you will calculate activity space.
3. Select a Study Size by selecting either “Exact extent of points” or “Extent of points plus 10%”.
4. Choose the location where you will save the new shape layer.
5. Click ”Calculate.

Link Points

SPACE’s Link Points connects two points that share common attributes. This allows you to calculate the distances from one point to another, between similar cases, or between two points in a series of events.

Creating Link Points with SPACE

1. From the SPACE toolbar, click the “Link Points” button.
2. Select the Source layer and field.
3. Select the Target layer and field.
4. Choose the location where you will save the new shape layer.
5. Click “Calculate”.

Mean Nearest Neighbor

SPACE’s Mean Nearest Neighbor function calculates a number of statistics based on your set of cases. Mean Nearest Neighbor increases in accuracy as the number of points increase.

Mean Nearest Neighbor Calculations:

• The distance from each point to its nearest neighboring point.
• The mean nearest neighbor distance of your points.
• Standard deviation and z-score of your points.
• Comparison to the expected random results for your sample size and study area.
• Complete Spatial Randomness (CSR) test.
• The distribution of your points (Clustered, Uniform, or Random).

Calculating Mean Nearest Neighbor with SPACE

1. From the SPACE toolbar, click the “Mean Nearest Neighbor” button.
2. Select the layer for which you will calculate MNN.
3. Select the “Extent” of the layer that would like to analyze.
1. Selecting “Use current view as area for calculations” calculates MNN against your current view.
2. Selecting “Use selected layer’s extent as the area for calculations” calculates MNN against your selected layer.
4. Click “Calculate”.
5. The results for MNN analysis will appear in the white box within the MNN form.

Minimum Convex Polygon

SPACE’s Minimum Convex Polygon draws a bounding polygon around the outer-most points in your series. The outlying events serve as vertices for the polygon and all other events fall within the polygon.

Creating a Minimum Convex Polygon with SPACE

1. From the SPACE toolbar, click the “Minimum Convex Polygon” button.
2. Select the layer for which you will calculate MCP.
3. Choose the location where you will save the new shape layer.
4. Click “Calculate”.

Sequence

SPACE’s Sequence analyzes the movement from one case to another. It draws lines from event to event in the order of their occurrence.

Calculating Sequence allows you to analyze the length, direction, angle, bearing, order, and interval of the lines between your points. This can help you identify whether your series is growing or shrinking, and will aid in your efforts to predict future events. This will also allow you to derive a number of important ratios based on your crimes.

Calculating Sequence with SPACE

1. From the SPACE toolbar, click the “Sequence” button.
2. Select the layer for which you will calculate Sequence.
3. Select the layer’s “Sequence” field.
4. Choose the location where you will save the new shape layer.
5. Click “Calculate”.

Spider Diagram

SPACE’s Spider Diagram connects a group of points to their centroid with lines. This helps describe the relationship of points to their center. The Spider Diagram allows you to choose whether you would like to calculate based on an arithmetic or harmonic centroid.

Arithmetic Centroid - Uses the mean x and mean y of your points as the center.

Harmonic Centroid - Uses a weighted algorithm calculated against the mean x and mean y of your points as the center.

SPACE’s Spider Diagram helps you determine whether the offender is a Marauder or Commuter, and whether the series is growing outward, or shrinking inward.

Creating a Spider Diagram with SPACE

1. From the SPACE toolbar, click the “Spider Diagram” button.
2. Select the layer for which you will create a Spider Diagram.
3. Select the Centroid (either Arithmetic or Harmonic) to designate the type of Spider Distance to use.
1. Selecting “Arithmetic” uses the mean X and mean Y of the points as the center.
2. Selecting “Harmonic” uses a weighted algorithm against the mean X and mean Y of your points as the center.
4. Choose the location where you will save the new shape layer.
5. Click “Calculate”.

Standard Deviation Ellipse

SPACE’s Standard Deviation Ellipse creates an ellipse based on the central tendency your cases.

Standard Deviation Ellipse calculations

• A Least Squares Trend Line is calculated across the distribution of your cases.
• Mean X and mean Y coordinates are calculated.
• Standard deviations from the error against the trend line are derived.
• A selected standard deviation is used to define the outer bounds of the ellipse.

Calculating Standard Deviation Ellipse with SPACE

1. From the SPACE toolbar, click the “Standard Deviation Ellipse” button.
2. Select the Input layer for which you will calculate SDE.
3. Choose the location where you will save the new shape layer.
4. Select the “Ellipse Size” by choosing between either 1, 2, or 3 Standard Deviations.
5. (Optional) Choose the “Weight Field”.
6. (Optional) Choose the “Case Field”.
7. Click “OK”.