summaryrefslogtreecommitdiff
path: root/dtrain/hstreaming/lplp.rb
diff options
context:
space:
mode:
Diffstat (limited to 'dtrain/hstreaming/lplp.rb')
-rwxr-xr-xdtrain/hstreaming/lplp.rb131
1 files changed, 131 insertions, 0 deletions
diff --git a/dtrain/hstreaming/lplp.rb b/dtrain/hstreaming/lplp.rb
new file mode 100755
index 00000000..40409bbd
--- /dev/null
+++ b/dtrain/hstreaming/lplp.rb
@@ -0,0 +1,131 @@
+# lplp.rb
+
+# norms
+def l0(feature_column, n)
+ if feature_column.size >= n then return 1 else return 0 end
+end
+
+def l1(feature_column, n=-1)
+ return feature_column.map { |i| i.abs }.reduce { |sum,i| sum+i }
+end
+
+def l2(feature_column, n=-1)
+ return Math.sqrt feature_column.map { |i| i.abs2 }.reduce { |sum,i| sum+i }
+end
+
+def linfty(feature_column, n=-1)
+ return feature_column.map { |i| i.abs }.max
+end
+
+# stats
+def median(feature_column, n)
+ return feature_column.concat(0.step(n-feature_column.size-1).map{|i|0}).sort[feature_column.size/2]
+end
+
+def mean(feature_column, n)
+ return feature_column.reduce { |sum, i| sum+i } / n
+end
+
+# selection
+def select_k(weights, norm_fun, n, k=10000)
+ weights.sort{|a,b| norm_fun.call(b[1], n) <=> norm_fun.call(a[1], n)}.each { |p|
+ puts "#{p[0]}\t#{mean(p[1], n)}"
+ k -= 1
+ if k == 0 then break end
+ }
+end
+
+def cut(weights, norm_fun, n, epsilon=0.0001)
+ weights.each { |k,v|
+ if norm_fun.call(v, n).abs >= epsilon
+ puts "#{k}\t#{mean(v, n)}"
+ end
+ }
+end
+
+# test
+def _test()
+ puts
+ w = {}
+ w["a"] = [1, 2, 3]
+ w["b"] = [1, 2]
+ w["c"] = [66]
+ w["d"] = [10, 20, 30]
+ n = 3
+ puts w.to_s
+ puts
+ puts "select_k"
+ puts "l0 expect ad"
+ select_k(w, method(:l0), n, 2)
+ puts "l1 expect cd"
+ select_k(w, method(:l1), n, 2)
+ puts "l2 expect c"
+ select_k(w, method(:l2), n, 1)
+ puts
+ puts "cut"
+ puts "l1 expect cd"
+ cut(w, method(:l1), n, 7)
+ puts
+ puts "median"
+ a = [1,2,3,4,5]
+ puts a.to_s
+ puts median(a, 5)
+ puts
+ puts "#{median(a, 7)} <- that's because we add missing 0s:"
+ puts a.concat(0.step(7-a.size-1).map{|i|0}).to_s
+ puts
+ puts "mean expect bc"
+ w.clear
+ w["a"] = [2]
+ w["b"] = [2.1]
+ w["c"] = [2.2]
+ cut(w, method(:mean), 1, 2.05)
+ exit
+end
+_test()
+
+# actually do something
+def usage()
+ puts "lplp.rb <l0,l1,l2,linfty,mean,median> <cut|select_k> <k|threshold> [n] < <input>"
+ puts " l0...: norms for selection"
+ puts "select_k: only output top k (according to the norm of their column vector) features"
+ puts " cut: output features with weight >= threshold"
+ puts " n: if we do not have a shard count use this number for averaging"
+ exit
+end
+
+if ARGV.size < 3 then usage end
+norm_fun = method(ARGV[0].to_sym)
+type = ARGV[1]
+x = ARGV[2].to_f
+
+shard_count_key = "__SHARD_COUNT__"
+
+STDIN.set_encoding 'utf-8'
+STDOUT.set_encoding 'utf-8'
+
+w = {}
+shard_count = 0
+while line = STDIN.gets
+ key, val = line.split /\t/
+ if key == shard_count_key
+ shard_count += 1
+ next
+ end
+ if w.has_key? key
+ w[key].push val.to_f
+ else
+ w[key] = [val.to_f]
+ end
+end
+
+if ARGV.size == 4 then shard_count = ARGV[3].to_f end
+
+if type == 'cut'
+ cut(w, norm_fun, shard_count, x)
+elsif type == 'select_k'
+ select_k(w, norm_fun, shard_count, x)
+else
+ puts "oh oh"
+end
+