Counting consecutive array elements from array

[arun10427]

Hi all

I am a perl newbie! And i am confused as to how to use arrays..

After some operation, my @array consists of lotta numbers..when i print @array, I get something like 1111111123448395911111111111245 etc..

I need to count the consecutive ones and store it in an array. Is there anything I could do?

 

[audiopro]

Not sure just what you are asking but one possible solution would be the 'foreach' function which will iterate through your array 1 character at a time. You can then perform whatever action you require for each character.

Keith

http://www.studiosoft.co.uk

 

[Zhris]

I need to count the consecutive ones and store it in an array.

To me this means you either want to count the number of elements in the array:

my $numberofelements = @array;
print "$numberofelements\n";

Or you want to add all the numbers together to produce a total:

my $total;
foreach my $current (@array) {
     $total += $current;
}
print "$total\n";

Either way, as audiopro pointed out, a foreach loop is often used to process an array, 1 element at a time.

Chris

 

[arun10427]

Thanks for your replies guys.
I guess I could explain my problem more clearly.
If I have the array elements as 1,1,1,1,1,1,2,1,1,1,3,1,1,1

Then I want the output as 6 3 3 , the number of times 1 occurs until a different integer occurs, and again the count continues.
Hope that helps.
Thanks

 

[audiopro]

Is it just consecutive '1's you are counting or any consecutive numbers?

Keith

http://www.studiosoft.co.uk

 

[arun10427]

Any consecutive number.

 

[audiopro]

I am trying to help you work the answer out for yourself rather than just provide a solution. The best way to learn in my opinion.
In your example of output, how do you know which number was repeated?
What are you doing with the data?

Keith

http://www.studiosoft.co.uk

 

[parkers]

Hi,

I've had a quick play and think something like this would be what you are looking for:

#!/usr/bin/perl

use strict;

my @array = (1,1,1,1,1,1,2,1,1,1,3,3,1,1,1,1,1,2,2,2,3,4,5,8,9,9);

my $consecutiveItems = [];
my $consecutiveHash = {};
my $lastElem = undef;
my $count = 0;

# gather data...
foreach my $elem (@array) {
	
	if ($elem != $lastElem) {
		push @$consecutiveItems, $consecutiveHash if $consecutiveHash->{$lastElem} > 1;
		
		# reset hash
		$consecutiveHash = {};
	}
	
	++$consecutiveHash->{$elem};
	
	# exit condition check...
	if ($count == $#array) {
		push @$consecutiveItems, $consecutiveHash if $consecutiveHash->{$lastElem} > 1;
	}
	
	$lastElem = $elem;
	++$count;
}

# print out results...
foreach my $item (@$consecutiveItems) {
	my ($number, $value) = each %$item;
	
	print "\nNumber: $number\tConsecutive Matches: $value";
}

This is very simple and builds an array of hashes that store consecutive matches. This could be adapted quickly to work for strings.

Hope this helps!

Thanks.

Steven Parker

http://www.stevenp1974.co.uk

 

[Zhris]

A rough script which counts the number of times a number is seen consecutively, then resets when a new number is seen. With your input data the output will be 6 1 3 1 3. Still not 100% clear what you are trying to achieve though. If you would like to count how many times a number occurs throughout the entire array, build a hash within the foreach loop like $hash{$_} += 1;.

#! /usr/bin/perl
use strict;

my @input = (1,1,1,1,1,1,2,1,1,1,3,1,1,1);
my ($marker1,%hash,@output);
my $marker2 = 0;

foreach (@input) {
     if ($marker1 != $_) {
          $marker1 = $_;
          $marker2++;
     }
     $hash{$marker2} += 1;
}

foreach my $key(sort(keys(%hash))) {
     push(@output,$hash{$key});
}

#Prints 6 1 3 1 3
print "@output\n";

Chris

 

[arun10427]

Hi All!

Thanks for the efforts. It surely is Useful!

Why I need to do this

- I am using a perl code to read a DBF file which has timestamps in 1 of its column- field. I am using xBase for it..My code needs to check the consecutive timestamps and if the count of the consecutive timestamps is less than 100,I need to delete those records. So I wrote a script which populates the difference between current timestamp and prev timestamp when i traverse through the list.
This is my code till now

#!C:\perl\bin
use Date::Day;
use warnings;
use XBase;
my $data7 = @_;
my $sum = 0;
my $table = new XBase "input.dbf";
my $first = $table->get_record(0,"TimeStamp");
my $second = $table->get_record(1,"TimeStamp");
my $iff = $second - $first;

print $iff;
my $final;
my $array = @_;
my $count = 0;
my $data9 = @_;
my @array=();
for (my $i=2;$i<$table->last_record;$i++)
{
	@data7 = $table->get_record($i,"TimeStamp");
	@data8 = $table->get_record($i-1,"TimeStamp"); 	
        $data9 = $data7[1] - $data8[1];
	push(@array,$data9);	
	
}
#my @array2 =(1,1,1,1,1,1,1,1,1,2,1,1);
my $cout=0;
$array[0]=1;

for(my $j=1;$j<@array;$j=$j+1)
{
if($array[$j]==1)
{
if($array[$j]==$array[$j-1])
{
	$cout=$cout+1;
}
else {next;}
}

}

I am totally new to perl. Any input for the same would be helpful..

 

[travs69]

maybe you should just do it here

my @array=();
my $old_diff;
my $old_count;
for (my $i=2;$i<$table->last_record;$i++){    
@data7 = $table->get_record($i,"TimeStamp");    
@data8 = $table->get_record($i-1,"TimeStamp");             $data9 = $data7[1] - $data8[1];    
if ($data9 == $old_diff) {
 $old_count++;
}
else {
 if ($old_count >= '100') {
  #Do something here with your data
  print "$old_diff $old_count;
 }
 $old_count = 0;
}

$old_diff = $data9;
#Just leave the push here if you need it for something else
push(@array,$data9);        
}

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Travis - Those who say it cannot be done are usually interrupted by someone else doing it; Give the wrong symptoms, get the wrong solutions;