fix clearing function

[floswald]

this needs to be cleaned up and put in a proper unit test in the /test/ dir of the repo

i will work on this issue with Xiaojie

[jeannesorin]

@lorenzokaaks and I have a clue if you need

As @jeannesorin and @lorenzokaaks suggested I changed the output of the function to be the squareroot of the sum of squares instead of being an array of errors

created new branch with new function and test

[floswald]

when you are ready to share this addition you need to create a pull request from that new branch.