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Why are elementwise additions much faster in separate loops than in a combined loop?
...from a page-boundary.
Here's the test code:
int main(){
const int n = 100000;
#ifdef ALLOCATE_SEPERATE
double *a1 = (double*)malloc(n * sizeof(double));
double *b1 = (double*)malloc(n * sizeof(double));
double *c1 = (double*)malloc(n * sizeof(double));
double *d1 = (double*)mall...
Multiple INSERT statements vs. single INSERT with multiple VALUES
I'm running a performance comparison between using 1000 INSERT statements:
4 Answers
4...
What's the fastest way to merge/join data.frames in R?
...rm(N))
d2 <- data.frame(x=sample(N,N), y2=rnorm(N))
g1 <- sample(1:1000, N, replace = TRUE)
g2<- sample(1:1000, N, replace = TRUE)
d <- data.frame(d1, g1, g2)
library(rbenchmark)
benchmark(replications = 1, order = "elapsed",
merge = merge(d1, d2),
plyr = join(d1, d2),
data.t...
How do I make a list of data frames?
...m(50))
But who does only one simulation? You want to do this 100 times, 1000 times, more! But you don't want 10,000 data frames in your workspace. Use replicate and put them in a list:
sim_list = replicate(n = 10,
expr = {data.frame(x = rnorm(50), y = rnorm(50))},
...
What is the significance of ProjectTypeGuids tag in the visual studio project file
...4A-11D0-8D11-00A0C91BC942}
Web Application {349C5851-65DF-11DA-9384-00065B846F21}
Web Site {E24C65DC-7377-472B-9ABA-BC803B73C61A}
WCF {3D9AD99F-2412-4246-B90B-4EAA41C64699}
WPF {60DC8134-EBA5-43B8-BCC9-BB4BC16C2548}
XNA (Windows) {6...
How to parse/format dates with LocalDateTime? (Java 8)
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@micha what if i have "2016-12-31T07:59:00.000Z" this date formate?
– Dawood Ahmed
Apr 26 '16 at 12:29
15
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What is polymorphism, what is it for, and how is it used?
...c are instantiated.
petraeus.Advise(); // # Petraeus says send 100,000 troops to Fallujah
condolezza.Advise(); // # she says negotiate trade deal with Iran
healthOfficials.Advise(); // # they say we need to spend $50 billion on ObamaCare
}
}
This approach allows the pre...
Printing 1 to 1000 without loop or conditionals
Task : Print numbers from 1 to 1000 without using any loop or conditional statements. Don't just write the printf() or cout statement 1000 times.
...
JSP tricks to make templating easier?
...
+40million. Thank you for explaining it 50,000 times better than any crappy tutorial I've found. Coming from the Rails world and missing ERB, this is exactly what I need. You should write a blog.
– cbmeeks
Apr 8 '11 at 13:35
...
Good way of getting the user's location in Android
...nally require updates at -at least- the desired rate
long minTimeMillis = 600000; // 600,000 milliseconds make 10 minutes
locationManager.requestLocationUpdates(myProvider,minTimeMillis,0,locationListener);
Read the documentation for requestLocationUpdates for more details on how the arguments ar...