Find leukemia boundaries

Wombling assesses local rates of change. Choose Detect Boundary > Wombling from the Data menu OR after right clicking on the leukemia dataset in the project window.

1. General Tab

   • Data: leukemia

   • New boundary name: local leukemia boundaries.

   • Detect boundary using: Single variable. Choose Cases/1000.

   • Choose not to standardize data before detection (clear the checkbox).  Data standardization is only necessary when you analyze multiple variables.

2. Thresholds Tab:

   • Accept the defaults, choose to set thresholds using information provided below

   • Define a crisp boundary using the top 20% of Boundary Likelihood Values (BLVs).

   • Leave the box checked next to display histogram of BLVs.

3. Other Tab: Accept the gradient angle defaults.

   • Maximum angle between adjacent vectors: 90°

   • Minimum angle between gradient and boundary: 30°.

4. Look at the histogram of Boundary Likelihood Values, the Map, and the Table.