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Get the distance between two geo points
... I think that distanceTo returns the distance between the first and last point but in a rectal line , so if you take any other directions from point a to b its gonna never be accuarated since the path is different, thats when distanceBetween joins in, you can save each distance between the points be...
Java: How to get input from System.console()
...Using Console to read input (usable only outside of an IDE):
System.out.print("Enter something:");
String input = System.console().readLine();
Another way (works everywhere):
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
public class Test {
p...
Read Excel File in Python
...= (sheet.cell(row,col).value)
try:
value = str(int(value))
except ValueError:
pass
finally:
values.append(value)
item = Arm(*values)
items.append(item)
for item in items:
print item
print("Ac...
BLE协议—广播和扫描 - 创客硬件开发 - 清泛IT社区，为创新赋能！
..., /* 设备安全管理OOB标志 */
BLE_AD_TYPE_INT_RANGE = 0x12, /* 设备连接参数范围 */
BLE_AD_TYPE_SOL_SRV_UUID = 0x14,...
Cell spacing in UICollectionView
...ing in a section of UICollectionView ? I know there is a property minimumInteritemSpacing I have set it to 5.0 still the spacing is not appearing 5.0. I have implemented the flowout delegate method.
...
“Prevent saving changes that require the table to be re-created” negative effects
...ll of the questions raised by the OP, and those questions are the ones I'm interested in, actually. In particular Are there any negative effects / possible drawbacks of doing this? and If so, is the table copy a 100% exact replica of the source table?. Do you have any information regarding those que...
How to drop a PostgreSQL database if there are active connections to it?
...he pid values you want to kill, then issue SELECT pg_terminate_backend(pid int) to them.
PostgreSQL 9.2 and above:
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
WHERE pg_stat_activity.datname = 'TARGET_DB' -- ← change this to your DB
AND pid <> pg_backend_pid();...
SQL Joins Vs SQL Subqueries (Performance)?
...frastructure. We have a kind of query optimization engine underneath which converts the IN (...) clauses to join (if it was possible). But when you have a Group by on a well indexed column (based on its cardinality) then it will be much faster. So it really depends on the situation.
...
Why is Java's boolean primitive size not defined?
..., but due to
alignment rules it may consume much
more. IMHO it is more interesting to
know that a boolean[] will consume one
byte per entry and not one bit,plus
some overhead due to alignment and for
the size field of the array. There are
graph algorithms where large fields of
bits a...
Using smart pointers for class members
I'm having trouble understanding the usage of smart pointers as class members in C++11. I have read a lot about smart pointers and I think I do understand how unique_ptr and shared_ptr / weak_ptr work in general. What I don't understand is the real usage. It seems like everybody recommends using...