# map (0-map.us)

People say map to mean a picture that shows places and how to get between them. They also use it as a verb meaning to figure out where something belongs or how one thing lines up with another.

## What a model may hear
- key-value store (computer science, programming): assume a data structure that pairs keys with values for fast lookup
- higher-order function (functional programming): apply a function to every element in a list or collection and return the results
- memory-mapped file or region (operating systems): treat a file or device as if it were part of RAM, enabling direct byte access
- graph or hash table (algorithms): model a problem as a set of nodes and edges, or use hashing for O(1) access
- coordinate transformation (graphics, GIS, machine learning): project data from one space to another, like lat-long to pixels or feature vectors to latent space

## Where people and models part ways
- Says: "Map this data for me"
  Means: Make a visual chart or diagram
  May be taken as: Apply a function element-wise or build a hash table
  Say instead: "Create a visual map or chart of this data"
- Says: "Put it on the map"
  Means: Make it visible or important
  May be taken as: Write it to a memory-mapped region or insert into a key-value store
  Say instead: "Make this prominent or well-known"
- Says: "Map out the plan"
  Means: Explain the steps clearly
  May be taken as: Generate a formal graph structure or state machine
  Say instead: "Outline the steps clearly in words"
- Says: "The results don't map to what I expected"
  Means: They don't match or correspond
  May be taken as: The function returned wrong outputs or the hash lookup failed
  Say instead: "The results don't correspond to what I expected"

## Tips
- Say 'visual map' or 'chart' when you want a picture, not a data structure
- Say 'apply to each' or 'transform each element' instead of 'map' for list operations
- Say 'corresponds to' or 'matches' when you mean alignment, not key lookup
- Specify 'geographic map' or 'street map' to avoid confusion with data structures
- Avoid 'map' as a verb with models unless you mean the technical function

## Often confused with
- reduce: combines values into one result, not one-to-one transformation
- filter: selects subset of elements, does not transform them
- plot: always means visual graph, never a data structure
- dictionary: same data structure, but said in Python; 'map' is Java/C++
- transform: general change of form, not specifically element-wise function application
- hash: focuses on the hashing mechanism, not the key-value pairing itself