Figure 4.

Scatterplot of misclassified pressure gradient recordings for the thr8-23-SVM (a) and thr6-28-SVM models (b). The X axis was subdivided into six intervals, and the Y axis denoted the actual pressure gradient for each manometry instance in each group. False predictions were labeled with their true pressure gradient value, and the line did not point exactly to the dot; thus, the dots were jittered to avoid overlapping. For example, in Figure a (Group 2), there were four false predictions; the true gradient values were 5 mmHg, 5.5 mmHg, 4 mmHg, and 4 mmHg, but these 4 instances were predicted to be over the 8 mmHg threshold; therefore, they were false-positive predictions.