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Error: could not find function … in R
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There are a few things you should check :
Did you write the name of your function correctly? Names are case sensitive.
Did you install the package that contains the function? install.packages("thePackage") (this only needs to be done once)
Did you attach that package to the wo...
ListView item background via custom selector
Is it possible to apply a custom background to each Listview item via the list selector?
10 Answers
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Image fingerprint to compare similarity of many images
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Normal hashing or CRC calculation algorithms do not work well with image data. The dimensional nature of the information must be taken into account.
If you need extremely robust fingerprinting, such that affine transformations (scaling, rotation, translation, fli...
SQLite add Primary Key
I created a table in Sqlite by using the CREATE TABLE AS syntax to create a table based on a SELECT statement. Now this table has no primary key but I would like to add one.
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Is background-color:none valid CSS?
...background-color property:
Value: <color> | transparent | inherit
<color> can be either a keyword or a numerical representation of a colour. Valid color keywords are:
aqua, black, blue, fuchsia, gray, green, lime, maroon, navy, olive,
orange, purple, red, silver, teal, whit...
Why doesn't a python dict.update() return the object?
...atically tinged flavor of command-query separation: mutators return None (with pragmatically induced exceptions such as pop;-) so they can't possibly be confused with accessors (and in the same vein, assignment is not an expression, the statement-expression separation is there, and so forth).
That ...
Can someone explain __all__ in Python?
...e and more, and I keep seeing the variable __all__ set in different __init__.py files. Can someone explain what this does?
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Pointer to pointer clarification
...ntains is a memory address. The & is the "address of" operator - i.e. it returns the address in memory of an object. The * operator gives you the object a pointer refers to, i.e. given a pointer containing an address, it returns the object at that memory address. So when you do *ipp = ip2, wh...
What is a “symbol” in Julia?
... to use Julia's DataFrames package, specifically the readtable() function with the names option, but that requires a vector of symbols.
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How do I use Django templates without the rest of Django?
...plate engine in my (Python) code, but I'm not building a Django-based web site. How do I use it without having a settings.py file (and others) and having to set the DJANGO_SETTINGS_MODULE environment variable?
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