Maps: where is {0,0}?

Current discussion on maps opening in the ‘right’ place—i.e. where the user assumed would show—makes reference of the X and Y axis zero position, i.e. map co-ordinates 0,0 (zero, zero). It may be not everyone knows here these are on a default map>

Better, making a new note and giving it the edict:

$Xpos = 0;
$Ypos = 0;

The note will reposition so its top left corner is a {0,0}:

This is because $Xpos and $Ypos plot at the top left corner of the map icon. For differently shaped notes the position with be just inside the bounding box for the icon:

Note, if I drag the window larger (same, new file), the map scrolls to keep {0,0} roughly in the middle:

The map is conceptually) infinite, i.e. it is as big as it need to be to hold existing content. As it grows the map view with show vertical (y-axis) and horizontal (X-axis) scroll bars at right and bottom as/when needed.

So, {0,0} is likely close to where you first add content, but it doesn’t really matter apart from the map needing to zero its co-ordinates somewhere on the map.

See more on Map Coordinates. Note that the Y-axis values are flipped from normal cartesian grids in the down on the Y axis it positive $Ypos, and up is negative $Ypos. I presume the reflects the fact that (in most Western cultures) we write/enter indo starting at top left and then go left → right, top → bottom.

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As a map only shows the contents of a single Outline container each container has(the potential) to show its own map: this is how you can drill down into a container in map view and see a new map. Each map has its own co-ordinates. This in part explains why you can’t “just flatten” all the maps into the document into one map as multiple items across different maps might have the same {X,Y} position.

If I drop a new note into the above test, see how it drops so the top left corner is in the middle of the container viewport (which here I’ve had to resize a bit, altering the effect):

In the above the child note is reporting its position by using a Display Expression:

$Name+" X:"+$Xpos.precision(2)+", Y:"+$Ypos.precision(2)

By comparison, is I select a note on the current map, anywhere on there, and hit the down-arrow (↓), I ‘drill down’ into an empty child map, where {0,0} is roughly in the middle of the view pane.

So the co-ordinates of the map aren’t navigationally useful—though they are for fine-positioning via action code or doing automated layouts, etc. Even then exactly where {0,0} appears on a given map view really isn’t important (to the app, anyway!).

Here’s the TBX used here and in the post above, in case it helps others experiment: zero-zero-on-maps.tbx (151.3 KB)

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Thanks

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