Add implementation note on how missing values are handled

1 files changed, 10 insertions, 0 deletions

diff --git a/README.md b/README.md
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+# AnnotateChange
+
+## Implementation Notes
+
+* Missing values are skipped, so that gaps occur in the graph. X-values are 
+  however counted continuously, to ensure that this gap has nonzero width. 
+  Thus, when a change point is selected by an annotator after such a gap, its 
+  location can be found by retrieving the observation at the index *while 
+  including missing values*. This is in contrast to the approach where missing 
+  values are removed before the index is used to retrieve the data point.