in reply to Re: Splice an array into another array
in thread Splice an array into another array

I think I am getting it now, thank you

Final question for clarity's sake: in the end I have to manually enter each nucleotide, am I understanding this right? In other words I can't be lazy and store several DNA files I downloaded online into arrays and then operate on them. For each of my array I have to manually type the nucleotide sequences in myself or copy+paste them in

below I includes 2 examples of what I mean, in the first example I manually stored the nucleotides into arrays, and everything works. In the second example the nucleotides are stored into arrays via filehandler and things do not work (in the way I want)

this will splice the 2 arrays together in whatever fashion I want 

 #!/usr/bin/perl -w

@DNA3 = qw(A T C C A T G C);

@DNA4 = qw(G C C G A A T T A);

splice (@DNA3, 1, 0, @DNA4);

print @DNA3, "\n";

exit;

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this will not work, I cannot use this to splice 2 arrays together 

 #!/usr/bin/perl -w

$DNA3file = 'testDNA3';

open(DNA3handle, $DNA3file);

@DNA3 = <DNA3handle>;

$DNA4file = 'testDNA4';

open(DNA4handle, $DNA4file);

@DNA4 = <DNA4handle>;

splice (@DNA3, 1, 0, @DNA4);

print @DNA3, "\n";

exit;

[download]

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Re^3: Splice an array into another array
by huck (Prior) on Jun 23, 2017 at 23:25 UTC
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      Could you explain this code a bit?  @DNA3=split('',join('',@DNA3)); I don't quite get what it means and why this is necessary for my script to work.

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        @DNA3 = <DNA3handle>;  # read all LINES of file into array
chomp @DNA3;           # remove any and all newlines
@DNA3=split('',join('',@DNA3));  # join('',@DNA3)  join all LINES into
+ one long line
                                 # split('', ...)  split long line int
+o list
                                 #                 of individual chara
+cters
                                 # @DNA3= ...      assign list of indi
+vidual
                                 #                 characters to an ar
+ray

        [download]
        @DNA3 will end up looking something like  ('A', 'T', 'C', 'G', ...) See chomp, join, split.

        Update: Fixed up formatting of long comment lines for last statement.

        Give a man a fish:  <%-{-{-{-<

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Re^3: Splice an array into another array
by AnomalousMonk (Archbishop) on Jun 23, 2017 at 23:35 UTC
    ... in the end I have to manually enter each nucleotide, am I understanding this right? In other words I can't be lazy and store several DNA files I downloaded online into arrays and then operate on them. For each of my array I have to manually type the nucleotide sequences in myself or copy+paste them in

    You have to realize that when you read a file with | with a sequence of statements like
        $DNA3file = 'testDNA3';
        open(DNA3handle, $DNA3file);
        @DNA3 = <DNA3handle>;
    the  @DNA3 array ends up with all the lines of the file, and each line is a string that looks like  "ATCCATGC\n" (note the newline that will be at the end of (almost) every line).

    If you have the lines of the file as strings, you | your program can operate on them as strings, break them up into arrays and operate on them, etc., as appropriate for your application. Your choice.

    Give a man a fish:  <%-{-{-{-<

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      nope, I didn't, but thanks for the explanation, I understand it much more clearly now! :)

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