update README.md

build_map before find with mask

check diagonals

explain diagonals

setup v1.7

correct sample framelet in doc

correct sequence description in merged data

update readme

format code

add comments to code

update readme

v1.6 doc update

v0.6 ready to publish

doc the code

do not panic with Result

alllow dead for boxchar

delete dead_code attr

make build_map public