matlab difficulties

[zhupolongjoe]

I need a Matlab function that finds the last place in a line where a double character appears (that is, where the same character appears twice in a row)

 

So if the function is called locateDouble, locateDouble('adcdccd') should return 5 since inxes 5 is the first charcter of the last double character.

I posted my attempt at the program below, but it won't work.

 

 

function double=locateDouble(line)

place=length(line);

while place>0;

for j=1:length(line)-1;

if j~==j+1

j=j+1

end

end

end

 

thanks

[Mark Baker]

The best place to ask matlab questions is a matlab forum rather than a PHP forum.

 

If you want a PHP function to do what you're asking:

function locateDouble($line) {
$place = strlen($line) - 1;
$found = false;
while (($place > 1) && (!$found)) {
	if ($line{$place} == $line{$place--}) {
		$found = True;
	}
}
if ($found) {
	return $place;
} else {
	return False;
}
}

echo locateDouble('adcdccd').'<br />';

[genericnumber1]

it definitely would be better to ask this in a matlab community...

 

That said:

function [ index ] = testfunc( line )

index = -1
for i = 1 : length(line)-1
    if line(i) == line(i+1)
        index = i
    end
end

end

 

If you want the first occurance of duplicate characters:

function [ index ] = testfunc( line )

index = -1
for i = 1 : length(line)-1
    if line(i) == line(i+1)
        index = i
        break
    end
end

end

[genericnumber1]

Or more efficiently for the last occurrence (since I just remembered how to change the delta on the for loop):

 

function [ index ] = testfunc( line )

index = -1
for i = length(line) : -1 : 2
    if line(i) == line(i-1)
        index = i-1
        break
    end
end

end

 

I'm done, I promise.

[zhupolongjoe]

Got it, thanks!