Thanks for the fix in 0.46.7. There are a couple more subtle problems having to do with bounds checking (one of which may be there by design).

Bounds checking occurs in the function array_rangeop_getrange() starting line 536:

firstitem = x->x_onset;

if (firstitem < 0)

firstitem = 0;

else if (firstitem > a->a_n)

firstitem = a->a_n;

if (x->x_n < 0)

nitem = a->a_n - firstitem;

else

{

nitem = x->x_n;

if (nitem + firstitem > a->a_n)

nitem = a->a_n - firstitem;

}

So unlike tabread which clips indices from 0 to n-1, this clips the onset from 0 to n, which means an onset greater than (n-1) gets a range with 0 items. I think this might be by design, but I wanted to check because a range with 0 items does something funny in the min/max array objects.

So first off, in these lines (starting line 746):

for (i = 0, besti = 0, bestf= -1e30, itemp = firstitem;

i < nitem; i++, itemp += stride)

if (*(t_float *)itemp > bestf)

bestf = *(t_float *)itemp, besti = i;

If the input range has 0 items (i.e. if nitems is set to zero manually, or if the onset is greater than n-1), the for-loop condition i < nitem is never true, so the value output is going to be the bestf init value -1e30 (likewise with +1e30 in the min function). Since this a value that doesn't point to anything in the array, I wonder if it would be better not to output anything (or maybe a bang) in those cases.

Second, the value x->x_rangeop.x_onset is not bounds checked, so when you do this (line 750):

outlet_float(x->x_out2, besti + x->x_rangeop.x_onset);

if x_rangeop.x_onset iss out of range, you're going to output an erroneous index value, which could be negative or greater than n. firstitem is bounds-checked from the onset by array_rangeop_getrange() -- would it be possible to use that instead?

This suite is really a wonderful addition to Pd, and adds so much new functionality to vanilla.

Many cheers!

Matt

On Fri, Sep 4, 2015 at 8:11 PM, Miller Puckette <msp@ucsd.edu> wrote:

Yep :)

M

On Fri, Sep 04, 2015 at 07:46:30PM -0400, Matt Barber wrote:
> Thanks.
>
> I meant to say that there was the same problem in [array min], but you
> probably caught it in your fix.
>
> Best,
>
> Matt
>
> On Fri, Sep 4, 2015 at 7:19 PM, Miller Puckette <msp@ucsd.edu> wrote:
>
> > Yep... thanks. Fixed in git - may take some time for me to get out a new
> > compiled version (other stuff to fix too :)
> >
> > M
> >
> >
> > On Fri, Sep 04, 2015 at 05:51:15PM -0400, Matt Barber wrote:
> > > Hi list,
> > >
> > > I've been playing around with the new(ish) [array] object suite in
> > vanilla
> > > 0.46.6. Forgive me if this is already a known issue, but it looks like
> > the
> > > min and max arguments aren't working properly.
> > >
> > > The second inlet (setting the number of points to search) works as
> > > expected. The first inlet doesn't update: it seems to be set to 0 no
> > matter
> > > what (although the index outlet is updated, but not as expected).
> > >
> > > I think I see the problem in x_array.c
> > >
> > > The max object is defined line 723:
> > >
> > > typedef struct _array_max
> > > {
> > > t_array_rangeop x_rangeop;
> > > t_outlet *x_out1; /* value */
> > > t_outlet *x_out2; /* index */
> > > int x_onset; /* search onset */
> > > } t_array_max;
> > >
> > >
> > > And the bang and float methods starting 740:
> > >
> > > static void array_max_bang(t_array_max *x)
> > > {
> > > char *itemp, *firstitem;
> > > int stride, nitem, i, besti;
> > > t_float bestf;
> > > if (!array_rangeop_getrange(&x->x_rangeop, &firstitem, &nitem,
> > &stride))
> > > return;
> > > for (i = 0, besti = 0, bestf= -1e30, itemp = firstitem;
> > > i < nitem; i++, itemp += stride)
> > > if (*(t_float *)itemp > bestf)
> > > bestf = *(t_float *)itemp, besti = i;
> > > outlet_float(x->x_out2, besti+x->x_onset);
> > > outlet_float(x->x_out1, bestf);
> > > }
> > >
> > > static void array_max_float(t_array_max *x, t_floatarg f)
> > > {
> > > x->x_onset = f;
> > > array_max_bang(x);
> > > }
> > >
> > >
> > > In the float method it looks like the onset is never actually assigned in
> > > the x_rangeop member of the t_array_max struct, so array_rangeop_getrange
> > > can't set the firstitem pointer to anything but its init value.
> > >
> > >
> > > Thanks,
> > >
> > > Matt
> >
> > > _______________________________________________
> > > Pd-list@lists.iem.at mailing list
> > > UNSUBSCRIBE and account-management ->
> > http://lists.puredata.info/listinfo/pd-list
> >
> >

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