Utility functions for manipulating chromosomal regions. | (ns cljam.util.region
(:require [clojure.string :as cstr]
[proton.core :as proton])) |
region predicates | |
Returns true if two regions are overlapped with each other. | (defn overlapped-regions?
[x y]
(and (= (:chr x) (:chr y))
(<= (:start y) (:end x))
(<= (:start x) (:end y)))) |
region conversion | |
Returns a lazy sequence of merged regions. Input regions must be sorted. Neighboring regions apart less than or equal to 'max-gap' will be merged with 'merge-fn'. Returns a stateful transducer when no input 'regions' is provided. | (defn merge-regions-with
([merge-fn]
(merge-regions-with merge-fn 0))
([merge-fn ^long max-gap]
(fn merge-regions-transducer [rf]
(let [last-reg (volatile! nil)]
(fn merge-regions-rf
([] (rf))
([r] (rf (if-let [l @last-reg] (rf r l) r)))
([r x] (if-let [l @last-reg]
(if (and (= (:chr l) (:chr x))
(<= (- (dec (:start x)) (:end l)) max-gap))
(do (vswap! last-reg merge-fn x) r)
(do (vreset! last-reg x) (rf r l)))
(do (vreset! last-reg x) r)))))))
([merge-fn ^long max-gap regs]
(if-let [f (first regs)]
(if-let [s (second regs)]
(if (and (= (:chr f) (:chr s))
(<= (- (dec (:start s)) (:end f)) max-gap))
(let [next-regs (cons (merge-fn f s) (nnext regs))]
(lazy-seq (merge-regions-with merge-fn max-gap next-regs)))
(cons f (lazy-seq (merge-regions-with merge-fn max-gap (next regs)))))
[f])
[]))) |
Default function to merge two regions. | (defn- merge-two-regions [x y] (update x :end max (:end y))) |
Same as 'merge-regions-with' except for 'merge-two-regions' is partially applied as merge-fn. | (def
^{:doc
:arglists '([] [max-gap] [max-gap regions])}
merge-regions
(partial merge-regions-with merge-two-regions)) |
Subtract a region from another one. Returns a vector of regions. | (defn subtract-region
[lhs-reg rhs-reg]
(if (= (:chr lhs-reg) (:chr rhs-reg))
(filterv
#(<= (:start %) (:end %))
[(update lhs-reg :end min (dec (:start rhs-reg)))
(update lhs-reg :start max (inc (:end rhs-reg)))])
[lhs-reg])) |
Returns a sequence of regions complement to in-regions. in-regions must be sorted. Returns a stateful transducer when no regions provided. | (defn complement-regions
([base-region]
(fn [rf]
(let [last-reg (volatile! base-region)]
(fn
([] (rf))
([r] (rf (if-let [l @last-reg] (rf r l) r)))
([r x]
(if-let [l @last-reg]
(let [[a b] (subtract-region l x)]
(vreset! last-reg (or b a))
(if b (rf r a) r))
r))))))
([base-region in-regions]
(if-let [reg (first in-regions)]
(if-let [[a b] (seq (subtract-region base-region reg))]
(if b
(cons a (lazy-seq (complement-regions b (next in-regions))))
(lazy-seq (complement-regions a (next in-regions))))
[])
[base-region]))) |
Divides a region [start end] into several chunks with maximum length 'step'. Returns a lazy sequence of vector. | (defn divide-region
[start end step]
(->> [(inc end)]
(concat (range start (inc end) step))
(partition 2 1)
(map (fn [[s e]] [s (dec e)])))) |
Divides refs into several chunks with maximum length 'step'. Returns a lazy sequence of map containing {:chr :start :end}. | (defn divide-refs
[refs step]
(mapcat
(fn [{:keys [name len]}]
(map (fn [[s e]] {:chr name :start s :end e})
(divide-region 1 len step)))
refs)) |
validation | |
Checks if the given rname conforms to the spec of sam. | (defn valid-rname? [rname] (and rname (string? rname) (re-matches #"[!-)+-<>-~][!-~]*" rname))) |
Checks if the given region map is a valid 1-based closed range. | (defn valid-region?
[{:keys [chr start end]}]
(and start end
(valid-rname? chr)
(number? start) (pos? start)
(number? end) (pos? end)
(<= start end))) |
region <=> string | |
Parse a region string into a map. | (defn parse-region
[region-str]
(when region-str
(let [pattern #"([!-)+-<>-~][!-~]*?)(:([\d,]+)?(-([\d,]+))?)?"
[_ chr _ start _ end] (re-matches pattern region-str)
start' (proton/as-long start)
end' (proton/as-long end)]
(when chr
(cond-> {:chr chr}
start' (assoc :start start')
end' (assoc :end end')))))) |
Parse a region string into a map strictly. | (defn parse-region-strict
[region-str]
(let [region-map (parse-region region-str)]
(when (valid-region? region-map) region-map))) |
Format a region map into a string. | (defn format-region
[{:keys [chr start end]}]
(let [result (->> [chr start end]
(take-while some?)
(interleave [nil \: \-])
(apply str))]
(when-not (cstr/blank? result) result))) |
Format a region map into a string strictly. | (defn format-region-strict [region-map] (when (valid-region? region-map) (format-region region-map))) |