大约有 31,500 项符合查询结果（耗时：0.0215秒） [XML]
Can someone give an example of cosine similarity, in a very simple, graphical way?
...e1)
counter2 = Counter(iterable2)
all_items = set(counter1.keys()).union(set(counter2.keys()))
vector1 = [counter1[k] for k in all_items]
vector2 = [counter2[k] for k in all_items]
return vector1, vector2
def cosim(v1, v2):
dot_product = sum(n1 * n2 for n1, n2 in zip(v1, v2)...
Difference between natural join and inner join
...have columns de-duplicated by name, hence no anonymous columns. Similarly, UNION CORRESPONDING and EXCEPT CORRESPONDING are provided to address SQL's dependence on column ordering in the legacy UNION syntax.
However, as with all programming techniques it requires discipline to be useful. One requir...
PreparedStatement IN clause alternatives?
...olumn FROM my_table WHERE search_column = ?, execute it for each value and UNION the results client-side. Requires only one prepared statement. Slow and painful.
Prepare SELECT my_column FROM my_table WHERE search_column IN (?,?,?) and execute it. Requires one prepared statement per size-of-IN-list....
Why does Clojure have “keywords” in addition to “symbols”?
...t constructs are needed. Couldn't Clojure have created something with the union of the capabilities of both Keyword and Symbol?
– user73774
Oct 16 '09 at 19:57
25
...
LINQ to read XML
...=>
new string[]{ l.Attribute("name").Value }
.Union(
l.Descendants("level2")
.Select(l2=>" " + l2.Attribute("name").Value)
)
);
foreach (var lv in lvs)
{
result.AppendLine(lv);
...
How do I convert between big-endian and little-endian values in C++?
...wap_endian(T u)
{
static_assert (CHAR_BIT == 8, "CHAR_BIT != 8");
union
{
T u;
unsigned char u8[sizeof(T)];
} source, dest;
source.u = u;
for (size_t k = 0; k < sizeof(T); k++)
dest.u8[k] = source.u8[sizeof(T) - k - 1];
return dest.u;
}
us...
Can a C# class inherit attributes from its interface?
...e = typeof(T);
return type.GetCustomAttributes(attributeType, true).
Union(type.GetInterfaces().
SelectMany(interfaceType => interfaceType.GetCustomAttributes(attributeType, true))).
Distinct().Cast<T>();
}
...
Is there a REAL performance difference between INT and VARCHAR primary keys?
...ue. One of my biggest databases has entries for Yugoslavia and the Soviet Union. I'm glad they're not primary keys.
– Paul Tomblin
Dec 1 '08 at 21:39
8
...
What's the best way to join on the same table twice?
...
You could use UNION to combine two joins:
SELECT Table1.PhoneNumber1 as PhoneNumber, Table2.SomeOtherField as OtherField
FROM Table1
JOIN Table2
ON Table1.PhoneNumber1 = Table2.PhoneNumber
UNION
SELECT Table1.PhoneNumber2 as Phon...
PHP: merge two arrays while keeping keys instead of reindexing?
... Be VERY careful with this! The + operator is not an addition, it's a union. If the keys don't overlap then all is good, but if they do...
– GordonM
May 3 '12 at 15:46
3
...