Find: Difference between revisions
(Created page with "<apll> Z←L⍷R </apll> <p> <br> <b>Find</b> looks for patterns <apll>R</apll> in <apll>L</apll>. <br> It returns a simple boolean array with the same shape as <apll>L</apll>...") |
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| Line 3: | Line 3: | ||
</apll> | </apll> | ||
<p> | <p> | ||
<br> <b>Find</b> looks for patterns <apll> | <br> <b>Find</b> looks for patterns <apll>L</apll> in <apll>R</apll>. | ||
<br> It returns a simple boolean array with the same shape as <apll> | <br> It returns a simple boolean array with the same shape as <apll>R</apll>. | ||
<br> <br> | <br> <br> | ||
<apll>L</apll> and <apll>R</apll> are arbitrary arrays. | <apll>L</apll> and <apll>R</apll> are arbitrary arrays. | ||
But to be useful, | But to be useful, | ||
the rank of <apll> | the rank of <apll>L</apll> | ||
should not be more than the rank of <apll> | should not be more than the rank of <apll>R</apll>, | ||
and both arguments should have the same type | and both arguments should have the same type | ||
(either both character or both numeric). | (either both character or both numeric). | ||
<br> <br> | <br> <br> | ||
If <apll> | If <apll>L</apll> is a scalar, | ||
then <apll>Z←L⍷R ←→ | then <apll>Z←L⍷R ←→ R∊L</apll>. | ||
<br/> | <br/> | ||
If <apll> | If <apll>L</apll> is not a scalar, | ||
then it represents a contiguous pattern, | then it represents a contiguous pattern, | ||
which may or may not be found in one or more places in <apll> | which may or may not be found in one or more places in <apll>R</apll>. | ||
<br> <br> | <br> <br> | ||
If the arguments are numeric, | If the arguments are numeric, | ||
| Line 28: | Line 28: | ||
<apll> | <apll> | ||
<br/> | <br/> R←3 8⍴'thirteenfourteenfifteen ' | ||
<br/> | <br/> R | ||
<br/> thirteen | <br/> thirteen | ||
<br/> fourteen | <br/> fourteen | ||
| Line 35: | Line 35: | ||
<br> <br> | <br> <br> | ||
<br/> | <br/> 't'⍷R | ||
<br/> 1 0 0 0 1 0 0 0 | <br/> 1 0 0 0 1 0 0 0 | ||
<br/> 0 0 0 0 1 0 0 0 | <br/> 0 0 0 0 1 0 0 0 | ||
| Line 41: | Line 41: | ||
<br> <br> | <br> <br> | ||
<br/> | <br/> 'teen'⍷R | ||
<br/> 0 0 0 0 1 0 0 0 | <br/> 0 0 0 0 1 0 0 0 | ||
<br/> 0 0 0 0 1 0 0 0 | <br/> 0 0 0 0 1 0 0 0 | ||
Revision as of 15:51, 4 December 2016
Z←L⍷R
Find looks for patterns L in R.
It returns a simple boolean array with the same shape as R.
L and R are arbitrary arrays.
But to be useful,
the rank of L
should not be more than the rank of R,
and both arguments should have the same type
(either both character or both numeric).
If L is a scalar,
then Z←L⍷R ←→ R∊L.
If L is not a scalar,
then it represents a contiguous pattern,
which may or may not be found in one or more places in R.
If the arguments are numeric,
then the result is sensitive to ⎕CT.
Examples:
R←3 8⍴'thirteenfourteenfifteen '
R
thirteen
fourteen
fifteen
't'⍷R
1 0 0 0 1 0 0 0
0 0 0 0 1 0 0 0
0 0 0 1 0 0 0 0
'teen'⍷R
0 0 0 0 1 0 0 0
0 0 0 0 1 0 0 0
0 0 0 1 0 0 0 0
