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Hi, I am trying to use CART to find an ideal cut-off value for a simple diagnostic test (ie when the test score is above x, diagnose the condition). When I put in the model fit=rpart(outcome ~ predictor1(TB144), method="class", data=data8) sometimes it gives me a tree with multiple nodes for the same predictor (see below for example of tree with 1 or multiple nodes). Is there a way

Hi, I'm trying to recreate a sensitivity-specificity graph using the histbackback function. The only problem is that these graphs are typically drawn with vertical rather than horizontal bar plots (and the histbackback function only seems to work with horiz=TRUE argument, using "horiz=FALSE" doesn't work). Does anyone know if: 1) there's a different graphing function that