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How do I calculate the normal vector of a line segment?
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if we define dx=x2-x1 and dy=y2-y1, then the normals are (-dy, dx) and (dy, -dx).
Note that no division is required, and so you're not risking dividing by zero.
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ValueError: numpy.dtype has the wrong size, try recompiling
I just installed pandas and statsmodels package on my python 2.7
When I tried "import pandas as pd", this error message comes out.
Can anyone help? Thanks!!!
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Finding out whether a string is numeric or not
...ring is made up of numbers only. I am taking out a substring from a string and want to check if it is a numeric substring or not.
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Overloading Macro on Number of Arguments
I have two macros FOO2 and FOO3 :
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How do you remove a Cookie in a Java Servlet
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A negative value means that the cookie is not stored persistently and will be deleted when the Web browser exits. A zero value causes the cookie to be deleted.
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Why does C++11 not support designated initializer lists as C99? [closed]
... constructor. This is the sort of abstraction C++ promotes.
On the other hand the designated initializers feature is more about exposing and making members easy to access directly in client code. This leads to things like having a person of age 18 (years?) but with height and weight of zero.
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break out of if and foreach
I have a foreach loop and an if statement. If a match is found i need to ultimately break out of the foreach.
4 Answers
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Version vs build in Xcode
I have an app that I developed with Xcode 3 and recently started editing with Xcode 4. In the target summary I have the iOS application target form with fields: identifier, version, build, devices, and deployment target. The version field is blank and the build field is 3.4.0 (which matches the vers...
Regular expression for a hexadecimal number?
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@NiklasB. Your shorthand is only valid if using perl regex, if using POSIX regex, then Steven's solution is the shortest. Either way, Steven's solution works for both perl and POSIX regex.
– David M. Syzdek
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Comparing strings with == which are declared final in Java
...n Java. The following segment of simple code just concatenates two strings and then compares them with == .
6 Answers
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