Talk:Ways of writing numbers

2021-07-07T20:24:49Z

John McKenna: Created page with "In the Twitter thread: "Have you seen fractional numbers in hex or octal notation?" Literals like 0x1.123abcp-5 are now standard in C and C++. The exponent (following 'p') is..."

In the Twitter thread: "Have you seen fractional numbers in hex or octal notation?"
Literals like 0x1.123abcp-5 are now standard in C and C++. The exponent (following 'p') is written in decimal. The Handbook of Floating Point Arithmetic (Muller and about a thousand others) uses this format (sometimes without the 0x) to provide exact floating point constants.

Parentheses are overused

2021-07-06T14:09:01Z

John McKenna:

[[Category:Ambiguities]]

Parentheses are used to represent all sorts of operations and objects, many of which conflict with each other.

Grouping parts of an expression: \( (x+1)(x+2) \)

Argument of a function: \(f(x)\) is "\(f\) applied to \(x\)". ([[There is no function application symbol]])

Greatest common divisor: \((a,b) = \gcd(a,b)\)

Counting combinations: \( {n \choose k} = \frac{n!}{k!(n-k)!} \)

Repeated differentiation : \( f^{(n)}(x) = \frac{\mathrm{d}^nf}{\mathrm{d}x^n} \)

Vectors or one-column matrices: \( \begin{pmatrix} a \\ b \end{pmatrix} \)

Ideals: \((2)\) is the ideal generated by 2, \((a,b,c)\) is the ideal generated by \(\{a,b,c\}\).

Tuples: \((a,b)\)

Cycle notation for permutations: \((a,b)\) or \((a \; b)\)

Legendre/Jacobi symbol: \( \left(\dfrac{a}{b}\right) \)

Why start at x, y, z - User contributions [en-gb]

Talk:Ways of writing numbers

Parentheses are overused