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Can't find the 'libpq-fe.h header when trying to install pg gem
...nx), 11.10 (Oneiric Ocelot), 12.04 (Precise Pangolin), 14.04 (Trusty Tahr) and 18.04 (Bionic Beaver)):
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/usr/include/postgresql/libpq-fe.h
...
So try installing libpq-dev or its equivalent for your OS:
For Ubuntu/Debian systems: sudo apt-get install libpq-dev
On Red Hat Linux (RHEL) systems:...
Android screen size HDPI, LDPI, MDPI [duplicate]
... that I need fit in all screen sizes. I have three folders, hdpi , ldpi and mdpi for drawables, but in the emulator there isn't any referense to what resolution hdpi is and what mdpi and ldpi are.
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.gitignore after commit [duplicate]
...r committing many files, I am realizing that I need to create .gitignore and exclude .exe , .obj files.
6 Answers
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iOS start Background Thread
... is responsible for setting up the new thread's autorelease pool, run loop and other configuration details – see "Using NSObject to Spawn a Thread" in Apple's Threading Programming Guide.
You'd probably be better off using Grand Central Dispatch, though:
dispatch_async(dispatch_get_global_queue(...
How do I associate a Vagrant project directory with an existing VirtualBox VM?
...irtualBox VM, so that when I vagrant up Vagrant will import the base-box and create a new virtual machine.
10 Answers
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Java Replacing multiple different substring in a string at once (or in the most efficient way)
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Future reader : for regex, "(" and ")" will enclose the group to search. The "%" counts as a literal in the text. If your terms don't start AND end with the "%" they will not be found. So adjust prefixes and suffixes on both parts (text + code).
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How to normalize a NumPy array to within a certain range?
...io /= np.max(np.abs(audio),axis=0)
image *= (255.0/image.max())
Using /= and *= allows you to eliminate an intermediate temporary array, thus saving some memory. Multiplication is less expensive than division, so
image *= 255.0/image.max() # Uses 1 division and image.size multiplications
i...
Are there any coding standards for JavaScript? [closed]
What are the established coding standards for JavaScript?
8 Answers
8
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How does the “final” keyword in Java work? (I can still modify an object.)
...antics of final. In other words: final is only about the reference itself, and not about the contents of the referenced object.
Java has no concept of object immutability; this is achieved by carefully designing the object, and is a far-from-trivial endeavor.
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How to convert a byte array to a hex string in Java?
I have a byte array filled with hex numbers and printing it the easy way is pretty pointless because there are many unprintable elements. What I need is the exact hexcode in the form of: 3a5f771c
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