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Feature #3647 » array_sample_with_replace_hash.patch

mrkn (Kenta Murata), 08/03/2010 04:53 PM

View differences:

array.c
static ID id_cmp;
static VALUE sym_replace;
#define ARY_DEFAULT_SIZE 16
#define ARY_MAX_SIZE (LONG_MAX / (int)sizeof(VALUE))
......
switch (n) {
case 0:
return rb_ary_new2(0);
return rb_ary_new2(0);
case 1:
return rb_ary_new4(1, &ptr[(long)(rb_genrand_real()*len)]);
return rb_ary_new4(1, &ptr[(long)(rb_genrand_real()*len)]);
default:
break;
break;
}
result = rb_ary_new2(n);
ptr_result = RARRAY_PTR(result);
RB_GC_GUARD(ary);
for (i = 0; i < n; ++i) {
long const j = (long)(rb_genrand_real()*len);
ptr_result[i] = ptr[j];
long const j = (long)(rb_genrand_real()*len);
ptr_result[i] = ptr[j];
}
ARY_SET_LEN(result, n);
return result;
......
static VALUE
rb_ary_sample(int argc, VALUE *argv, VALUE ary)
{
VALUE nv, replace, result, *ptr;
VALUE nv, opts, replace=Qfalse, result, *ptr;
long n, len, i, j, k, idx[10];
len = RARRAY_LEN(ary);
......
i = len == 1 ? 0 : (long)(rb_genrand_real()*len);
return RARRAY_PTR(ary)[i];
}
rb_scan_args(argc, argv, "12", &nv, &replace);
rb_scan_args(argc, argv, "12", &nv, &opts);
n = NUM2LONG(nv);
if (n < 0) rb_raise(rb_eArgError, "negative sample number");
if (RTEST(replace)) {
return ary_sample_with_replace(ary, n);
if (!NIL_P(opts) && TYPE(opts) == T_HASH) {
replace = rb_hash_aref(opts, sym_replace);
}
if (RTEST(replace))
return ary_sample_with_replace(ary, n);
ptr = RARRAY_PTR(ary);
len = RARRAY_LEN(ary);
if (n > len) n = len;
......
rb_define_method(rb_cArray, "drop_while", rb_ary_drop_while, 0);
id_cmp = rb_intern("<=>");
sym_replace = ID2SYM(rb_intern("replace"));
}
test/ruby/test_array.rb
def test_sample_without_replace
100.times do
samples = [2, 1, 0].sample(2, false)
samples = [2, 1, 0].sample(2, replace: false)
samples.each{|sample|
assert([0, 1, 2].include?(sample))
}
......
a = (1..18).to_a
(0..20).each do |n|
100.times do
b = a.sample(n, false)
b = a.sample(n, replace: false)
assert_equal([n, 18].min, b.size)
assert_equal(a, (a | b).sort)
assert_equal(b.sort, (a & b).sort)
......
h = Hash.new(0)
1000.times do
a.sample(n, false).each {|x| h[x] += 1 }
a.sample(n, replace: false).each {|x| h[x] += 1 }
end
assert_operator(h.values.min * 2, :>=, h.values.max) if n != 0
end
assert_raise(ArgumentError, '[ruby-core:23374]') {[1, 2].sample(-1, false)}
assert_raise(ArgumentError, '[ruby-core:23374]') {[1, 2].sample(-1, replace: false)}
end
def test_sample_with_replace
100.times do
samples = [2, 1, 0].sample(2, true)
samples = [2, 1, 0].sample(2, replace: true)
samples.each{|sample|
assert([0, 1, 2].include?(sample))
}
......
a = (1..18).to_a
(0..20).each do |n|
100.times do
b = a.sample(n, true)
b = a.sample(n, replace: true)
assert_equal(n, b.size)
assert_equal(a, (a | b).sort)
assert_equal(b.sort.uniq, (a & b).sort)
......
h = Hash.new(0)
1000.times do
a.sample(n, true).each {|x| h[x] += 1 }
a.sample(n, replace: true).each {|x| h[x] += 1 }
end
assert_operator(h.values.min * 2, :>=, h.values.max) if n != 0
end
assert_raise(ArgumentError, '[ruby-core:23374]') {[1, 2].sample(-1, true)}
assert_raise(ArgumentError, '[ruby-core:23374]') {[1, 2].sample(-1, replace: true)}
end
def test_cycle
(2-2/3)