distance

[[concept]]

A metric or distance is a function d:M×M→R that satisfies

  1. d(x,x)=0
  2. d(x,y)>0∀x≠y
  3. d(x,y)=d(y,x)
  4. d(x,z)≤d(x,y)+d(y,z)

This is part of the definition of a metric space.

functional analysis

Metric

If X is a set then d:X×X→[0,∞) is a metric if

  1. (identifiability) d(x,y)=0⟺x=y
  2. (symmetry) ∀x,y∈X,d(x,y)=d(y,x)
  3. (triangle inequality) ∀x,y,z∈X,d(x,y)≤d(x,z)+d(z,y)

Reference

see also

Mentions

Mentions

const modules = await cJS()

const COLUMNS = [  
	{ id: "Name", value: page => page.$link },  
	{ id: "Last Modified", value: page => modules.dateTime.getLastMod(page) },
];  
  
return function View() {  
	const current = dc.useCurrentFile();
// Selecting `#game` pages, for example. 
	let queryString = `@page and linksto(${current.$link})`;
	let pages = dc.useQuery(queryString);
	
	// check types
	pages = pages.filter( (p) => !modules.typeCheck.checkAll(p, current) ).sort()
	
	
	return <dc.Table columns={COLUMNS} rows={pages} paging={20}/>;  
}  


const { dateTime } = await cJS()

return function View() {
	const file = dc.useCurrentFile();
	return <p class="dv-modified">Created {dateTime.getCreated(file)}     ֍     Last Modified {dateTime.getLastMod(file)}</p>
}