Find method - Revision history

Diemo at 13:25, 3 January 2011

2011-01-03T13:25:40Z

Diemo at 13:24, 3 January 2011

2011-01-03T13:24:57Z

Diemo: Owen Green

2011-01-03T13:23:54Z

Owen Green

Diemo at 13:22, 2 July 2010

2010-07-02T13:22:53Z

Diemo at 10:10, 15 December 2009

2009-12-15T10:10:26Z

Beller at 08:42, 5 May 2009

2009-05-05T08:42:39Z

Beller at 08:42, 5 May 2009

2009-05-05T08:42:08Z

New page

find <expr: expression> <any: arguments to expression...> - leave indices
where expression is true (use $x, $i and $self)

The find method of fmat replaces an fmat with the (unwrapped) indices of the
elements for which the given expression returned non-zero. The expression can
use the arguments to the find method following the expression as $1, $2, etc.,
and the predefined super-local variables $x (the value of the element being
tested), $i (its index), and $self (the reference to the fmat itself).
Otherwise, only global definitions are visible within the expression. (The
latter holds for any expression evaluation.)

Example: ($myfmat find $myexpr 1 20) with myexpr = '(($x >= $1) && ($i < $2))'
finds values greater than 1 in the first 20 indices and replaces $myfmat with
their indices.

@@ Line 30: / Line 30: @@
    [expr '($x > 0.5)' | myexpr]
-You could do
+You could do on fmat $foo
-   (($foo rows 20) ramp 0 1); ($foo find ($myexpr))
+   (($foo rows 20) ramp 0 1); ($foo find $myexpr)
 Which would return all those indices where x > 0.5, i.e. the second half of the fmat in this case.

@@ Line 16: / Line 16: @@
 finds values greater or equal 1 in the first 20 indices and replaces $myfmat with
 their indices.
 [[Category:FAQ]] [[Category:FTM Documentation]] [[Category:fmat Class]] [[Category:expr Class]] [[Category:ftm.mess]]

← Older revision		Revision as of 13:22, 2 July 2010
Line 16:		Line 16:
	finds values greater or equal 1 in the first 20 indices and replaces $myfmat with		finds values greater or equal 1 in the first 20 indices and replaces $myfmat with
	their indices.		their indices.
		+
		+	[[Category:FAQ]] [[Category:FTM Documentation]] [[Category:fmat Class]] [[Category:expr Class]] [[Category:ftm.mess]]

@@ Line 13: / Line 13: @@
 latter holds for any expression evaluation.)
-Example: <code>($myfmat find $myexpr 1 20)</code> with myexpr = '(($x >= $1) && ($i < $2))'
+Example:
 finds values greater or equal 1 in the first 20 indices and replaces $myfmat with
 their indices.

@@ Line 1: / Line 1: @@
-find <expr: expression> <any: arguments to expression...>
+This is a method of the [[FTM_Classes#Class_fmat| fmat class]].
 - leave indices where expression is true (use $x, $i and $self)
@@ Line 11: / Line 13: @@
 latter holds for any expression evaluation.)
-Example: ($myfmat find $myexpr 1 20) with myexpr = '(($x >= $1) && ($i < $2))'
+Example: <code>($myfmat find $myexpr 1 20)</code> with myexpr = '(($x >= $1) && ($i < $2))'
-finds values greater than 1 in the first 20 indices and replaces $myfmat with
+finds values greater or equal 1 in the first 20 indices and replaces $myfmat with
 their indices.