[Octave-bug-tracker] [bug #35174] polyfit broken by chageset 614505385171

[marco atzeri]

URL:
  <http://savannah.gnu.org/bugs/?35174>

                 Summary: polyfit broken by chageset 614505385171
                 Project: GNU Octave
            Submitted by: matzeri
            Submitted on: Mon 26 Dec 2011 07:36:18 AM GMT
                Category: None
                Severity: 3 - Normal
                Priority: 5 - Normal
              Item Group: Incorrect Result
                  Status: None
             Assigned to: None
         Originator Name: 
        Originator Email: 
             Open/Closed: Open
         Discussion Lock: Any
                 Release: dev
        Operating System: Any

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Details:

changeset 14104:614505385171
doc: Overhaul docstrings for polynomial functions.

has the side effect to broke a test inside polyfit.

isrow can not work as it is applied after y=y(:)
so this portion should be reversed

   10.30  
   10.31 -  y_is_row_vector = (rows (y) == 1);
   10.32 -
   10.33    ## Reshape x & y into column vectors.
   10.34    l = numel (x);
   10.35    x = x(:);
   10.36 @@ -98,7 +97,7 @@
   10.37    if (nargout > 1)
   10.38      yf = v*p;
   10.39  
   10.40 -    if (y_is_row_vector)
   10.41 +    if (isrow (y))
   10.42        s.yf = yf.';
   10.43      else
   10.44        s.yf = yf;




>>>>> processing /pub/hg/octave/scripts/polynomial/polyfit.m
  ***** test
 x = 1000 + (-5:5);
 xn = (x - mean (x)) / std (x);
 pn = ones (1,5);
 y = polyval (pn, xn);
 [p, s, mu] = polyfit (x, y, numel(pn)-1);
 [p2, s2] = polyfit (x, y, numel(pn)-1);
 assert (p, pn, s.normr)
 assert (s.yf, y, s.normr)
 assert (mu, [mean(x), std(x)])
 assert (s.normr/s2.normr < sqrt(eps))
!!!!! test failed
assert (s.yf,y,s.normr) expected
 Columns 1 through 8:
    3.50419    1.60995    0.84300    0.67356    0.77025    1.00000    1.42810 
  2.31817
 Columns 9 through 11:
    4.13221    7.53054   13.37184
but got
    3.50419
    1.60995
    0.84300
    0.67356
    0.77025
    1.00000
    1.42810
    2.31817
    4.13221
    7.53054
   13.37184
Dimensions don't match




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