Toying with the Borel summation to calculate tetration

[mike3]

ok. but I got "tetploy" or a group of numbers and not 1 real or complex number correct only because "tetpoly" is empty.
please, you do to correct your code.

To use it, try setting tetpoly with an initial guess first, e.g. tetpoly = 1 or tetpoly = 1 + 1.09*x. Then apply tetpoly = iternorm(tetpoly, A, order) (order is the order of the Borel summation.) some times to improve the accuracy. You can use nnormiters to do a batch of normalized iterations.