Commute-Duplicate: Difference between revisions

Revision as of 11:15, 1 December 2016

Duplicate: Z←f⍨ R

returns R f R.

Commute: Z←L f⍨ R

returns R f L.

L and R are arrays.

f is a function.

For example:

×⍨⍳5 ⍝ squares
1 4 9 16 25
∘.=⍨⍳4 ⍝ Identity matrix
1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1

2*⍨⍳5 ⍝ squares
1 4 9 16 25
√+/2*⍨6 2⍴3 4, 5 12, 8 15, 7 24, 20 21, 12 35 ⍝ Pythagorean hypotenuses
5 13 17 25 29 37

@@ Line 4: / Line 4: @@
      <table border="0" cellpadding="5" cellspacing="0" summary="">
      <tr>
-       <td valign="top">Commute: <apll>Z←f⍨ R</apll></td>
+       <td valign="top">Duplicate: <apll>Z←f⍨ R</apll></td>
        <td></td>
        <td>&nbsp;&nbsp;&nbsp;&nbsp;</td>
@@ Line 17: / Line 17: @@
      <table border="0" cellpadding="5" cellspacing="0" summary="">
      <tr>
-       <td valign="top">Duplicate:  <apll>Z←L f⍨ R</apll></td>
+       <td valign="top">Commute:  <apll>Z←L f⍨ R</apll></td>
        <td></td>
        <td></td>
@@ Line 37: / Line 37: @@
 <p>For example:</p>
-<apll>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;∘.=⍨⍳4 ⍝ Identity matrix<br />
+<apll>
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;×⍨⍳5 ⍝ squares <br/>
+4 9 16 25<br/>
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;∘.=⍨⍳4 ⍝ Identity matrix<br />
 0 0 0<br />
 1 0 0<br />
 0 1 0<br />
 0 0 1<br />
+</apll>
+<apll>
+&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2*⍨⍳5 ⍝ squares <br/>
+4 9 16 25<br/>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;√+/2*⍨6 2⍴3 4, 5 12, 8 15, 7 24, 20 21, 12 35 ⍝ Pythagorean hypotenuses<br />
 13 17 25 29 37<br />
 </apll>