Data commit

Task/Brownian-tree/J/brownian-tree-1.j

@@ -0,0 +1,19 @@
+brtr=:4 :0
+  seed=. ?x
+  clip=. 0 >. (<:x) <."1 ]
+  near=. [: clip +"1/&(,"0/~i:1)
+  p=.i.0 2
+  mask=. 1 (<"1 near seed)} x$0
+  field=.1 (<seed)} x$0
+  for.i.y do.
+    p=. clip (p +"1 <:?3$~$p),?x
+    b=.(<"1 p) { mask
+    fix=. b#p
+    if.#fix do. NB. if. works around j602 bug: 0(0#a:)}i.0 0
+      p=. (-.b)# p
+      mask=. 1 (<"1 near fix)} mask
+      field=. 1 (<"1 fix)} field
+    end.
+  end.
+  field
+)

Task/Brownian-tree/J/brownian-tree-2.j

@@ -0,0 +1,2 @@
+   require'viewmat'
+   viewmat 480 640 brtr 30000