G'day HH CHANG,

You need to show the actual code you're running and the output it produces including any error and warning messages: see the "How do I post a question effectively?" guidelines for details.

The code "@a = (1 2 3 4)" is syntactically incorrect and perl will abort compilation when it is encountered. The code will not run and "$y = join ',' , @a;" will be ignored:

$ perl -e '@a = (1 2 3 4); $y = join ",", @a'
Number found where operator expected at -e line 1, near "1 2"
    (Missing operator before  2?)
Number found where operator expected at -e line 1, near "2 3"
    (Missing operator before  3?)
Number found where operator expected at -e line 1, near "3 4"
    (Missing operator before  4?)
syntax error at -e line 1, near "1 2"
Execution of -e aborted due to compilation errors.
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If you're actually writing code like that, you may well have all sorts of other problems. From your last post, you seem to know about strict and warnings: use these pragmata in all your scripts.

While I can't tell for certain from what you've posted here, a simplistic fix to the problem you describe may be:

@a = (qw{1 2 3 4})
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There's a lot about your post I don't understand, and I have no experience whatever with the URI::GoogleChart module, but I have never thought that mere ignorance should prevent one from offering advice, so here goes.

First off, I assume the

my $chart = URI::GoogleChart->new("lines", 300, 100,
      data => [45, 80, 55, 68],
      range_show => "left",
      range_round => 1,
  );
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... my data is an array or array_ref without comma, like: @a = (1 2 3 4) ...

As you have seen, this doesn't work because it is syntactically incorrect. The correct assignment expression would be  @a = (1, 2, 3, 4) or perhaps a statement like
    my @a = (1, 2, 3, 4);
if one were defining a lexical array (see my) and initializing it. The quick fix is to put in the needed commas.

But I suspect the quick fix doesn't work because your data is not in the form of a list, but rather is a string consisting of numbers with whitespace separating the numbers, something like  "1 2 3 4" (with the  " double-quotes being an essential part of the expression), e.g.,
    my $data = "1 2 3 4";

If so, the question becomes "How do I convert a string in the format '1 2 3 4' into a list that I can assign to an array?" The split Perl built-in function can do just this with a string in this format. (Use something like Data::Dumper or Data::Dump to confirm your intermediate results.)

>perl -wMstrict -le
"use Data::Dumper;
 ;;
 my $data = '1 2 3 4';
 my @a = split /\s+/, $data;
 print Dumper \@a;
"
$VAR1 = [
          '1',
          '2',
          '3',
          '4'
        ];
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Now you have an array from which you can take a reference:  my $array_ref = \@a;
This reference could be used in the  new() constructor of URI::GoogleChart:  data => $array_ref,
or else the result of the referencing operation could be used directly:  data => \@a,
or else the array itself could be expanded within an anonymous array constructor:  data => [ @a ],

I hope that helps. Update: Oh, and please pay attention to kcott's good advice about effective question-posting and the use of strict and warnings!

it's my fault. I should describe it more clearly.

I know where is the problem.

I parse a text and want to get identical words and its times. So I have a hash: key is "identical words" and value is "times".

I hope I could draw a lines picture (x-axis is identical word and y-axis is times). In other words, "times" is data argument and "identical words" is chxl argument in URI::GoogleChart.

    my ($x, @y);
    $x="0:";
    foreach (sort { $word2_hash{$b} <=> $word2_hash{$a} or $a cmp $b} 
+keys %word2_hash) {
        
        
        $x .= "|$_"; #add identical words
        push @y, $word2_hash{$_}; #add times 
        
    }


    my $chart = URI::GoogleChart->new("lines", 400, 150,
                data => \@y,#it is OK to parse array_ref
                range_show => "left",
                range_round => 1,
                color => ["red"],
                chxl => "$x", #
                chxt => "x",
                );
    #getstore($chart, "chart.png");
    #print "get pic\n";
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<Sorry for my wrong post. It could work if use array_ref/p>

I find where is my problem. The chxl seems have limit. If I decrease the identical words. I can get the picture. If I use a lot of identical words, I couldn't get the picture.

Thanks for all your reply.