Dear R users, I have a dataframe (main.table) with ~30,000 rows and 6 columns, of which here are a few rows:
id chr window gene xp.norm xp.top 129 1_32 1 32 TAS1R1 1.28882115 FALSE 130 1_32 1 32 ZBTB48 1.28882115 FALSE 131 1_32 1 32 KLHL21 1.28882115 FALSE 132 1_32 1 32 PHF13 1.28882115 FALSE 133 1_33 1 33 PHF13 1.02727430 FALSE 134 1_33 1 33 THAP3 1.02727430 FALSE 135 1_33 1 33 DNAJC11 1.02727430 FALSE 136 1_33 1 33 CAMTA1 1.02727430 FALSE 137 1_34 1 34 CAMTA1 1.40312732 TRUE 138 1_35 1 35 CAMTA1 1.52104538 FALSE 139 1_36 1 36 CAMTA1 1.04853732 FALSE 140 1_37 1 37 CAMTA1 0.64794094 FALSE 141 1_38 1 38 CAMTA1 1.23026086 TRUE 142 1_38 1 38 VAMP3 1.23026086 TRUE 143 1_38 1 38 PER3 1.23026086 TRUE 144 1_39 1 39 PER3 1.18154967 TRUE 145 1_39 1 39 UTS2 1.18154967 TRUE 146 1_39 1 39 TNFRSF9 1.18154967 TRUE 147 1_39 1 39 PARK7 1.18154967 TRUE 148 1_39 1 39 ERRFI1 1.18154967 TRUE 149 1_40 1 40 no_gene 1.79796879 FALSE 150 1_41 1 41 SLC45A1 0.20193560 FALSE I want to create two new columns, xp.bg and xp.n.top, using the following criteria: If gene is the same in consecutive rows, xp.bg is the minimum value of xp.norm in those rows; if gene is not the same, xp.bg is simply the value of xp.norm for that row; Likewise, if there's a run of contiguous xp.top = TRUE values, xp.n.top is the minimum value in that range, and if xp.top is false or NA, xp.n.top is NA, or 0 (I don't care). So, in the above example, xp.bg for rows 136:141 should be 0.64794094, and is equal to xp.norm for all other rows, xp.n.top for row 137 is 1.40312732, 1.18154967 for rows 141:148, and 0/NA for all other rows. Is there a way to combine indexing and if statements or some such to accomplish this? I want to it this without using split(main.table, main.table$gene), because there's about 20,000 unique entries for gene, and one of the entries, no_gene, is repeated throughout. I thought briefly of subsetting the rows where xp.top is TRUE, but I then don't know how to set the range for min, so that it only looks at what would originally have been consecutive rows, and searching the help has not proved particularly useful. Thanks in advance, Irene Gallego Romero -- Irene Gallego Romero Leverhulme Centre for Human Evolutionary Studies University of Cambridge Fitzwilliam St Cambridge CB1 3QH UK email: ig...@cam.ac.uk ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.