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| author | Marshall Lochbaum <mwlochbaum@gmail.com> | 2021-07-14 22:25:01 -0400 |
|---|---|---|
| committer | Marshall Lochbaum <mwlochbaum@gmail.com> | 2021-07-14 22:25:01 -0400 |
| commit | 8d58eafa341b5a65bed1a267bc34653e46bbc6e8 (patch) | |
| tree | beca1336e8b5ce493a27bbe9cebcc26149f3c7a8 /docs/doc/leading.html | |
| parent | f113d9f57bdae219c87887c5e0781a5c824dc8e4 (diff) | |
Document high-rank search function behavior
Diffstat (limited to 'docs/doc/leading.html')
| -rw-r--r-- | docs/doc/leading.html | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/docs/doc/leading.html b/docs/doc/leading.html index 72ce1450..69f04d77 100644 --- a/docs/doc/leading.html +++ b/docs/doc/leading.html @@ -201,12 +201,12 @@ <p>If one argument is a unit, that is, it has no axes, then leading axis agreement reduces to APL's "scalar extension" (where "scalar" is equivalent to BQN's "unit"), where a single unit is matched with an entire array by repeating it at every application. A unit always agrees with any other array under leading axis agreement because it has no axes whose lengths would need to be checked.</p> <p>With leading axis agreement, there are <code><span class='Value'>k</span><span class='Function'>+</span><span class='Number'>1</span></code> shapes for arrays that can be added (or any other function with Each) to a given array <code><span class='Value'>x</span></code> without changing its rank. These are precisely the prefixes of <code><span class='Function'>≢</span><span class='Value'>x</span></code>, with ranks from <code><span class='Number'>0</span></code> to <code><span class='Value'>k</span></code> inclusive. Arrays with larger rank can also be used as the other argument, but then the result shape will match that argument and not <code><span class='Value'>x</span></code>.</p> <h3 id="search-functions">Search functions</h3> -<p>The <a href="search.html">search functions</a> Bins (<code><span class='Function'>⍋⍒</span></code>), Index of (<code><span class='Function'>⊐</span></code>), Progressive Index of (<code><span class='Function'>⊒</span></code>), and Member of (<code><span class='Function'>∊</span></code>) look through cells of one argument to find cells of the other. Find (<code><span class='Function'>⍷</span></code>) also does a search, but a slightly different one: it tries to find <em>slices</em> of cells of <code><span class='Value'>𝕩</span></code> that match <code><span class='Value'>𝕨</span></code>.</p> +<p>The <a href="search.html">search functions</a>, Index of (<code><span class='Function'>⊐</span></code>), Progressive Index of (<code><span class='Function'>⊒</span></code>), and Member of (<code><span class='Function'>∊</span></code>), and also <a href="order.html#bins">Bins</a> (<code><span class='Function'>⍋⍒</span></code>), look through cells of one argument to find cells of the other. Find (<code><span class='Function'>⍷</span></code>) also does a search, but a slightly different one: it tries to find <em>slices</em> of cells of <code><span class='Value'>𝕩</span></code> that match <code><span class='Value'>𝕨</span></code>.</p> <table> <thead> <tr> -<th>Searching through</th> -<th>Look for</th> +<th>Search in</th> +<th>Search for</th> <th>Functions</th> </tr> </thead> @@ -223,4 +223,4 @@ </tr> </tbody> </table> -<p>For all of these functions but Find, the argument to search through is treated as a list of its major cells. It is the rank of these major cells—let's call this rank <code><span class='Value'>c</span></code>—that determines how the other argument is treated. That argument must have rank at least <code><span class='Value'>c</span></code>, and it is treated as an array of <code><span class='Value'>c</span></code>-cells. For example, if the left argument to <code><span class='Function'>⍋</span></code> is a matrix, then each 1-cell or row of <code><span class='Value'>𝕩</span></code> is treated independently, and each one yields one number in the result: a 0-cell. The result rank of <code><span class='Function'>⍋</span></code> is always <code><span class='Value'>𝕨</span><span class='Function'>¬</span><span class='Modifier2'>○</span><span class='Function'>=</span><span class='Value'>𝕩</span></code>.</p> +<p>For all of these functions but Find, the searched-in argument is treated as a list of its major cells, and the searched-for argument is considered a collection of cells with the same rank. See the <a href="search.html#higher-ranks">search function documentation</a>.</p> |
