"Manipulating Elements of Lists" shows how you can pick out elements of lists based on their positions. Often, however, you will need to select elements based not on where ...

If you have a function defined in an external program, then what you need to do in order to make it possible to call the function from within Mathematica is to add ...

The names of built-in functions follow some general guidelines. The main expression or object on which a built-in function acts is usually given as the first argument to the ...

If you have installed Mathematica in a location where multiple users can run it (for example, on a file server or multi-user machine), then you can set up systemwide defaults ...

ByteCount[expr] gives the number of bytes used internally by Mathematica to store expr.

Many programs you write will involve operations that need to be iterated several times. Nest and NestList are powerful constructs for doing this. Applying functions of one ...

When Mathematica transforms an expression such as x+x into 2x, it is treating the variable x in a purely symbolic or formal fashion. In such cases, x is a symbol which can ...

The Mathematica function NDSolve is a general numerical differential equation solver. It can handle a wide range of ordinary differential equations (ODEs) as well as some ...

NDSolve is broken up into several basic steps. For advanced usage, it can sometimes be advantageous to access components to carry out each of these steps separately. NDSolve ...

The arithmetic used by Mathematica is a mixture of variable-precision software arithmetic and whatever is provided by the manufacturer of the floating-point hardware (or the ...