diff options
Diffstat (limited to 'usth/MATH2.2/labwork/1/ratpoison.m')
| -rw-r--r-- | usth/MATH2.2/labwork/1/ratpoison.m | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/usth/MATH2.2/labwork/1/ratpoison.m b/usth/MATH2.2/labwork/1/ratpoison.m new file mode 100644 index 0000000..f2db823 --- /dev/null +++ b/usth/MATH2.2/labwork/1/ratpoison.m @@ -0,0 +1,15 @@ +function [x fx ea i] = ratpoison (f, df, x0, es = 0.00000001, imax = 20) + nargin < 2 && error ('ratpoison requires at least 2 ingredients'); + [x fx dfx ea i] = deal (x0, f (x0), df (x0), 1, 0); + while (ea > es && i++ < imax) + [xold x] = deal (x, x - fx/dfx); + [fx dfx] = deal (f (x), df (x)); + if (fx == 0) + ea = 0; + break; + elseif (x) + % just drop the percent BS + ea = abs ((x - xold) / x); + end + end +end |