Hello again,

Another probable noob style question... I have built a relatively simple external to generate low-passed random numbers (ie - skewed to the low end of a range). Nothing complicated, it takes two arguments - the range and a 'Q' value and when it receives a bang it spits out a random integer much like the native random object does. The external is working properly as far as I can tell, but it seems to be causing some amount of crashes. I had some difficulty getting it to work in the first place which was down to memory allocation issues and I suspect that may still be the problem now, but I have no idea why. the full code is as follows:

// ---------- include

#include "ext.h" #include "ext_obex.h"

// ---------- object

typedef struct _lprand { t_object obj; long *rndarray; long range; long q; void *out; } t_lprand;

// ---------- function prototypes

// standard set void *lprand_new(t_symbol *s, long argc, t_atom *argv); void lprand_free(t_lprand *x); void lprand_assist(t_lprand *x, void *b, long m, long a, char *s);

// additional void lprand_bang(t_lprand *x); long rnum(long range); long lopass(t_lprand *x, long range, long q);

// ---------- global class pointer

void *lprand_class;

// ---------- main

void ext_main(void *r) { t_class *c;

c = class_new("lprand", (method)lprand_new, (method)lprand_free, (long)sizeof(t_lprand), 0L, A_GIMME, 0);

class_addmethod(c, (method)lprand_bang, "bang", 0);

class_register(CLASS_BOX, c); lprand_class = c;

post("lprand object instantiated."); }

// ---------- assist

void lprand_assist(t_lprand *x, void *b, long m, long a, char *s) { if (m == ASSIST_INLET) { sprintf(s, "Inlet %ld accepts a bang", a); } else { sprintf(s, "Outlet %ld delivers a low-passed random number.", a); } }

// ---------- rnum (random number)

long rnum(long range) { long rand;

#ifdef WIN_VERSION rand_s(&rand); #else rand = random(); #endif

rand = rand % range;

return rand; }

// ---------- lopass (low passed random number)

long lopass(t_lprand *x, long range, long q) { long counter; long minimum;

for (counter = 0; counter < q; counter++) { x->rndarray[counter] = rnum(range); }

minimum = x->rndarray[0];

for (counter = 0; counter < q; counter++) { if (x->rndarray[counter] < minimum) { minimum = x->rndarray[counter]; } }

return minimum; }

// ---------- bang

void lprand_bang(t_lprand *x) { long rand = lopass(x, x->range, x->q);

outlet_int(x->out, rand); }

// ---------- free

void lprand_free(t_lprand *x) { sysmem_freeptr(x->rndarray); }

// ---------- new

void *lprand_new(t_symbol *s, long argc, t_atom *argv) { t_lprand *x = NULL; long range, q;

if (argc != 2) { post("Incorrect number of arguments for the lprand object."); return NULL; }

range = atom_getlong(argv); if (range < 1) { post("Range argument must be greater than 1."); return NULL;}

q = atom_getlong(argv+1); if (q < 1 || q > 10) { post("Q argument out of bounds. It must be between 1 and 10 (inclusive)."); return NULL; }

if ((x = (t_lprand *)object_alloc(lprand_class))) { x->rndarray = (long *)sysmem_newptrclear(q);

x->range = range; x->q = q;

x->out = intout((t_lprand *)x); }

return x; }

Can anyone see what might be causing this? I'm still (slowly) learning my way around the API. Originally I was attempting to just create the rndarray with malloc in the lopass function but after looking through the documentation and examples thought the sysmem_xxx stuff was a better way to ensure compatibility. Perhaps I have implemented it incorrectly?

Thanks for any thoughts.