Beispiel #1
0
void Gaussian<T>::generate(VectorT& x) const
{
  //generate a normalized gaussian distributed variable y
  VectorT y(numDims());
  for(int i=0;i<y.n;i++) y(i) = RandGaussian(0,1);
  L.mul(y,x);
  x += mu;
}
Beispiel #2
0
T Gaussian<T>::probability(const VectorT& x) const
{
  int d = numDims();
  T det=One;
  for(int i=0;i<d;i++) det*=L(i,i);
  T invc = Pow(2.0*Pi,0.5*T(d))*det;
  VectorT x_mu,y;
  x_mu.sub(x,mu);
  y.resize(L.n);
  LBackSubstitute(L,x_mu,y);
  return Exp(-Half*y.normSquared())/invc;
}
Beispiel #3
0
 const array::array_proxy array::operator()(const index &s0) const
 {
     index z = index(0);
     if(isvector()){
         switch(numDims(this->arr)) {
             case 1: return gen_indexing(*this, s0, z, z, z);
             case 2: return gen_indexing(*this, z, s0, z, z);
             case 3: return gen_indexing(*this, z, z, s0, z);
             case 4: return gen_indexing(*this, z, z, z, s0);
             default: AF_THROW_ERR("ndims for Array is invalid", AF_ERR_SIZE);
         }
     }
     else {
         return gen_indexing(*this, s0, z, z, z, true);
     }
 }
Beispiel #4
0
    // Assign values to an array
    array::array_proxy&
    af::array::array_proxy::operator=(const array &other)
    {
        unsigned nd = numDims(impl->parent_->get());
        const dim4 this_dims = getDims(impl->parent_->get());
        const dim4 other_dims = other.dims();
        int dim = gforDim(impl->indices_);
        af_array other_arr = other.get();

        bool batch_assign = false;
        bool is_reordered = false;
        if (dim >= 0) {
            //FIXME: Figure out a faster, cleaner way to do this
            dim4 out_dims = seqToDims(impl->indices_, this_dims, false);

            batch_assign = true;
            for (int i = 0; i < AF_MAX_DIMS; i++) {
                if (this->impl->indices_[i].isBatch) batch_assign &= (other_dims[i] == 1);
                else                          batch_assign &= (other_dims[i] == out_dims[i]);
            }

            if (batch_assign) {
                af_array out;
                AF_THROW(af_tile(&out, other_arr,
                                 out_dims[0] / other_dims[0],
                                 out_dims[1] / other_dims[1],
                                 out_dims[2] / other_dims[2],
                                 out_dims[3] / other_dims[3]));
                other_arr = out;

            } else if (out_dims != other_dims) {
                // HACK: This is a quick check to see if other has been reordered inside gfor
                // TODO: Figure out if this breaks and implement a cleaner method
                other_arr = gforReorder(other_arr, dim);
                is_reordered = true;
            }
        }

        af_array par_arr = 0;

        if (impl->is_linear_) {
            AF_THROW(af_flat(&par_arr, impl->parent_->get()));
            nd = 1;
        } else {
            par_arr = impl->parent_->get();
        }

        af_array tmp = 0;
        AF_THROW(af_assign_gen(&tmp, par_arr, nd, impl->indices_, other_arr));

        af_array res = 0;
        if (impl->is_linear_) {
            AF_THROW(af_moddims(&res, tmp, this_dims.ndims(), this_dims.get()));
            AF_THROW(af_release_array(par_arr));
            AF_THROW(af_release_array(tmp));
        } else {
            res = tmp;
        }

        impl->parent_->set(res);

        if (dim >= 0 && (is_reordered || batch_assign)) {
            if (other_arr) AF_THROW(af_release_array(other_arr));
        }
        return *this;
    }
Beispiel #5
0
 unsigned array::numdims() const
 {
     return numDims(get());
 }