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Speed up the loop operation in R
...
Biggest problem and root of ineffectiveness is indexing data.frame, I mean all this lines where you use temp[,].
Try to avoid this as much as possible. I took your function, change indexing and here version_A
dayloop2_A <- function(temp){
res <- numeric(nrow(te...
How do I capitalize first letter of first name and last name in C#?
...r))
{
var words = str.Split(' ');
for (int index = 0; index < words.Length; index++)
{
var s = words[index];
if (s.Length > 0)
{
words[index] = s[0].ToString().ToUpper() + s.Substrin...
how do I insert a column at a specific column index in pandas?
Can I insert a column at a specific column index in pandas?
4 Answers
4
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Convert a list to a dictionary in Python
...or this pretty easily:
a = ['hello','world','1','2']
my_dict = {item : a[index+1] for index, item in enumerate(a) if index % 2 == 0}
This is equivalent to the for loop below:
my_dict = {}
for index, item in enumerate(a):
if index % 2 == 0:
my_dict[item] = a[index+1]
...
MongoDB vs. Cassandra [closed]
...less data models (and encourage denormalization instead), and both provide indexes on documents or rows, although MongoDB's indexes are currently more flexible.
Cassandra's storage engine provides constant-time writes no matter how big your data set grows. Writes are more problematic in MongoDB, pa...
Difference between /res and /assets directories
...o declare a list of all the resource IDs that might be used and compute an index into the the list. (This is kind of awkward and introduces opportunities for error if the set of resources changes in the development cycle.) (EDIT: you can retrieve a resource ID by name using getIdentifier, but this l...
ERROR 2006 (HY000): MySQL server has gone away
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max_allowed_packet=64M
Adding this line into my.cnf file solves my problem.
This is useful when the columns have large values, which cause the issues, you can find the explanation here.
On Windows this file is located at: ...
Surrogate vs. natural/business keys [closed]
... for a logical primary key. They are both essentially just non-null unique index constraints.
– dkretz
Feb 12 '09 at 22:11
1
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Evenly distributing n points on a sphere
...g. Note that above I created an offset of my indices by adding 0.5 to each index. This was just visually appealing to me, but it turns out that the choice of offset matters a lot and is not constant over the interval and can mean getting as much as 8% better accuracy in packing if chosen correctly. ...
boost::flat_map and its performance compared to map and unordered_map
... flat land, whereas a standard unordered map just has to recreate the hash index, while the allocated data stays where it is. The disadvantage of course is that the memory is fragmented like hell.
The criterion of a rehash in an open address hash map is when the capacity exceeds the size of the buc...