Dear all, I am struggling with a problem and I am hoping that somebody could point me in the right direction. I am trying to match the locations of two peak patterns. A is the true pattern. B is the measured pattern. Hence A and B have a very strong linear relationship. The problem is that B can contain false positives: peaks due to noise instead of the true pattern from A. An additional problem is that some peaks from A could be missing in B. So what I am looking for is a way to select the largest possible subsets from A and B that give a good estimate of their relationship. Here is some example data. Notice that both B's have a different length. They should match both with A. A <- c(50, 100, 145, 200, 204, 255, 300, 350, 364, 400, 460, 495, 500, 530, 565, 600, 650, 700) B <- c(561, 622, 1050, 1290, 1574, 1594, 1613, 1910, 2165, 2438, 2520, 2706, 3013, 3182, 3203, 3343, 3496, 3645, 3844, 4026) B <- c(573, 633, 671, 707, 1060, 1303, 1594, 1615, 1633, 1936, 2195, 2472, 2554, 2743, 3053, 3225, 3246, 3388, 3543, 3693, 3894, 4078) Any suggestions? Best regards, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek / Research Institute for Nature and Forest Cel biometrie, methodologie en kwaliteitszorg / Section biometrics, methodology and quality assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 Thierry.Onkelinx at inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document.