In the figure attached "test", I would like to interpolate the empty - "NA" section to connect the two curves.
1/ I tried using "na.approx" and "na.spline", without success. na.approx(test,na.rm=FALSE) na.spline(test,na.rm=FALSE) In the first case it just draws a straight line between the end and beginning points of each curve, respectively, which doesn't look smooth. In the second case the cubic spline interpolation results overshoot above 1.0 which I would like to avoid (see attached test.na) . 2/ I have also used splinefun for a monotonic increasing spline, which is the best result so far Yfun <- splinefun(X,test,method="monoH.FC") test.spline <- Yfun(X) however the resulting curve displays a "kink" at the limit of the interpolation zone (see attached figure test.splinefun). is there a way to constrain the spline in na.spline in 1/, for example, to force it to be monotonic strictly increasing? Alternatively can we alter the smoothing performed by splinefun somehow to avoid this "kink"? Any other suggestions welcome! Thank you IC ________________________________ This message and any attachments contain information that may be RMS Inc. confidential and/or privileged. If you are not the intended recipient (or authorized to receive for the intended recipient), and have received this message in error, any use, disclosure or distribution is strictly prohibited. If you have received this message in error, please notify the sender immediately by replying to the e-mail and permanently deleting the message from your computer and/or storage system.
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