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Replace all 0 values to NA
...e number of elements so that there can be no "holes" (i.e., NULL values).
Now you could replace zeroes by NULL in a data frame in the sense of completely removing all the rows containing at least one zero. When using, e.g., var, cov, or cor, that is actually equivalent to first replacing zeroes wit...
Quickly create large file on a Windows system
...
It's not a sparse file (as far as I know) and the file is empty.
– Joey
Jan 4 '12 at 10:39
1
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Unique fields that allow nulls in Django
...ULL just after it comes out of the database, and the rest of Django won't know/care. A quick and dirty example:
from django.db import models
class CharNullField(models.CharField): # subclass the CharField
description = "CharField that stores NULL but returns ''"
__metaclass__ = models.S...
ExecutorService, how to wait for all tasks to finish
...l, so I just want to run a large number of jobs - one on each core. Right now my setup looks like this:
15 Answers
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Why does .NET foreach loop throw NullRefException when collection is null?
...I think of it, returning null for a collection is an error. The way it is now, the runtime gives you a meaningful exception in this case, but it's easy to work around (ie: above) if you don't like this behavior. If the compiler hid this from you, you'd lose the error checking at runtime, but there...
Untrack files from git temporarily
.... When I initialized git, I added pre-compiled libs and binaries. However, now during my development I don't want to check in those files intermittently. I dont want to remove these files from repo. Is there any way to not keep a track of these files till I complete my development. (I think I can no...
iPhone: Detecting user inactivity/idle time since last screen touch
...n];
}
else {
if (fabs([idleTimer.fireDate timeIntervalSinceNow]) < kMaxIdleTimeSeconds-1.0) {
[idleTimer setFireDate:[NSDate dateWithTimeIntervalSinceNow:kMaxIdleTimeSeconds]];
}
}
}
- (void)idleTimerExceeded {
[idleTimer release]; idleTimer = nil;
...
How to add a custom HTTP header to every WCF call?
...
OperationContext.Current.OutgoingMessageHeaders.Add(untyped);
// now make the WCF call within this using block
}
And then, server-side you grab it using:
MessageHeaders headers = OperationContext.Current.IncomingMessageHeaders;
string identity = headers.GetHeader<string>("Identity...
Creating default object from empty value in PHP?
...y the same thing which PHP is silently doing - unfortunatelly with warning now - implicit object creation. You should always check if the object already exists, unless you are absolutely sure that it doesn't. The code provided by Michael is no good in general, because in some contexts the object mig...
rgdal package installation
...h are dependencies! Unfortunately, rgdal still won't find pro_api.h right now since it isn't looking in /usr/local/include. To fix this and other possible maladies with your rgdal installation, use the following R command to install rgdal:
> install.packages('rgdal', type = "source", configu...