Re: Fractal Curves: Short & Fast Codes?

I'm pretty amazed by what you did - I just love the idea and the code seems just fine. However, being a newbie, I'm not really good at making it work.
I first installed the GD package I didn't have. But the code still isn't working fine. They are 2 lines which I don't understand :

        $xy->[0][scalar(@{$xy->[0]})] = $d*sin(PI*$h/180) + $xy->[0][$
+#{@{$xy->[0]}}];
        $xy->[1][scalar(@{$xy->[1]})] = $d*cos(PI*$h/180) + $xy->[1][$
+#{@{$xy->[1]}}];

Could you please explain them ? They appear in the first 2 scripts.
In the last one, what is plotxy ? It's not defined anywhere... Is it part of GD ? (I tried GD::plotxy but it still didn't work :( ).
Please let me know what I'm doing wrong - I'm currently using WinNT with ActivePerl.

Comment on Re: Fractal Curves: Short & Fast Codes?

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Re: Re: Fractal Curves: Short & Fast Codes? by chunlou (Curate) on Jun 17, 2003 at 11:45 UTC
No, I defined plotxy() in the code; it isn't part of GD. I only included it in Closure, omitted elsewhere since it's redundant to include it three times in the post. As for the two lines... If $xy = `[[4,5,6],[4,5,6]]`, scalar(@{$xy->`[0]`}) = scalar(@{$xy->`[0]`}) = 3, the number of elements. $xy->`[0]` points to the first array in $xy; $xy->`[1]` second. @{$xy->`[0]`} dereferences $xy->`[0]` into an array. So, $xy->`[0][scalar(@{$xy->[0]})]` will be like $xy->`[0][3]`, the new element in the array, yet to be defined, since the index of the last position is 2. $dsin(PI$h/180) is just some transformation stuff from trigonometry/geometry/calculus. $#{@{$xy->`[0]`}} gives you the index of the last element, which is 2 in this example. So, $xy->`[0][$#{@{$xy->[0]}}]` = $xy->`[0][$#{@{$xy->[1]}}]` gives you 6. (I've noticed you have "...$+#..." in your reply. When you see + in a code in the post, it indicates a continuation from the previous line. When you cut and past codes, those + might be inadvertently included. Remember to remove them.) Hence, the two lines basically say, new x coordinate = distance (on x axis) from old x coordinate + old x coordinate new y coordinate = distance (on y axis) from old y coordinate + old y coordinate	[reply] [d/l] [select]
Re: Re: Fractal Curves: Short & Fast Codes? by fglock (Vicar) on Jun 17, 2003 at 12:36 UTC
You can get rid of the "+" by using the "d/l code" link: `comment on Fractal Curves: Short & Fast Codes? ---> d/l code <---` [download]	[reply] [d/l]