Re: [Tutor] plotting pixels
On 10-09-18 07:39 PM, ALAN GAULD wrote: It appears that the Tk canvas widget does not support simply plotting a pixel. Correct, and I agree it seems odd, but in practice drawing either lines or ovals of one-pixel do the equivalent job - albeit a little more slowly. The primitive obviously exists in the underlying code, It probably exists in the native graphics toolkit (Xlib or Win32 or Aqua) but it doesn't exist at the Tk level which is why Tkinter can't expose it. FWIW wxPython does provide a DrawPoint() method as part of its DeviceContext class. Digging a little deeper it seems the idiomatic way to do this in Python is to use PIL the Python Imaging Library to create a GIF or bitmap image and then insert that into Tkinters cancvas as an image object. The Pil ImageDraw class has a point() ethod I've never tried this but it is described in Grayson's (now out of print?) book on Tkinter where he uses it to draw a Mandelbrot The book may be available online these days... Nowdownloadall.com seems to have it although I've no idea of the legality of it! HTH, Alan G. Here's a link, just don't download everything. It would be excessively large. http://isohunt.com/download/212380933/%22Python+and+Tkinter+Programming%22.torrent ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On 09/19/10 09:39, ALAN GAULD wrote: It appears that the Tk canvas widget does not support simply plotting a pixel. Correct, and I agree it seems odd, but in practice drawing either lines or ovals of one-pixel do the equivalent job - albeit a little more slowly. More slowly and takes huge amount of memory. A single Tk canvas object takes at least 14 words (= 114 bytes in 64-bit OS = 56 bytes in 32-bit OS) + the amount of data is needed to store the `kind of object`. That's much larger than the ideal 3 bytes per pixel (or 4 bytes with alpha). Tkinter's Canvas intentionally doesn't provide create_pixel() because unlike most other Canvas implementations, Tkinter's Canvas holds a stateful canvas objects instead of a simple drawing surface. Providing a create_pixel() will be too tempting for abuse, which would make the canvas unbearably slow and memory consuming. In short, Canvas is not designed for pixel drawing. Digging a little deeper it seems the idiomatic way to do this in Python is to use PIL the Python Imaging Library to create a GIF or bitmap image and then insert that into Tkinters cancvas as an image object. The Pil ImageDraw class has a point() ethod If you need to plot pixels, do use pygame, PIL, or at least the PhotoImage trick. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
Hello Ken,
On Sun, 19 Sep 2010 04:18:06 am Ken Oliver wrote:
HEAD
STYLEbody{font-size:10pt;font-family:arial,sans-serif;background-co
lor:#ff;color:black;}p{margin:0px;}/STYLE
META name=GENERATOR content=MSHTML 8.00.6001.18939/HEAD
BODYBRBRBR
BLOCKQUOTE style=BORDER-LEFT: #ff 2px solid; PADDING-LEFT: 5px;
[lots more HTML junk]
Ken, this is what I see when I read your emails. Could you please find
the setting in your email client to send plain text as well as HTML (or
what is wrongly called rich text by some email clients) and turn it
on? Unfortunately I've never used EarthLink Zoo Mail 1.0, so I can't
tell you how.
Not only is HTML-only posting considered rude by millions of people, but
it's also counter-productive. Pure HTML is one of the stronger
indications of Spam email, almost as strong as mentioning that word
that starts with V and sounds like Niagara Falls, and so chances are
good that some of your emails are being flagged as spam by anti-spam
checks.
--
Steven D'Aprano
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Re: [Tutor] plotting pixels
On Sun, Sep 19, 2010 at 2:40 AM, Lie Ryan lie.1...@gmail.com wrote: More slowly and takes huge amount of memory. A single Tk canvas object takes at least 14 words (= 114 bytes in 64-bit OS = 56 bytes in 32-bit OS) + the amount of data is needed to store the `kind of object`. That's much larger than the ideal 3 bytes per pixel (or 4 bytes with alpha). Tkinter's Canvas intentionally doesn't provide create_pixel() because unlike most other Canvas implementations, Tkinter's Canvas holds a stateful canvas objects instead of a simple drawing surface. Providing a create_pixel() will be too tempting for abuse, which would make the canvas unbearably slow and memory consuming. In short, Canvas is not designed for pixel drawing. Digging a little deeper it seems the idiomatic way to do this in Python is to use PIL the Python Imaging Library to create a GIF or bitmap image and then insert that into Tkinters cancvas as an image object. The Pil ImageDraw class has a point() ethod If you need to plot pixels, do use pygame, PIL, or at least the PhotoImage trick. Thanks for the feedback! That does make a lot a sense as to why a pixel_plot() type function would not be directly implemented in Canvas. As this is still largely a learning exercise for me, I may try more than one approach. I think first I will try the PhotoImage approach, which might be the most efficient method. However, I will definitely give Pygame a try. I have seen several programs that were written in Pygame and I am really impressed! It is obviously designed to task. -Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Fri, Sep 17, 2010 at 3:38 AM, Alan Gauld alan.ga...@btinternet.comwrote: For plotting pixels I would not use turtle graphics. That would be a fairly complicated option I'd have thought. A simple canvas would be easier. Alan G. Oh, I see! I did not realize that Tk had a canvas widget. That is nice. I will have to play with that and see if I can get everything done in the code I am working with. What I am doing is just trying to do a simple Mandelbrot set plot. It is another bit of coding that I do when learning a new language to get a handle on some of the graphics capabilities, and I am to that point. -Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Sat, Sep 18, 2010 at 10:44 AM, Bill Allen walle...@gmail.com wrote: On Fri, Sep 17, 2010 at 3:38 AM, Alan Gauld alan.ga...@btinternet.comwrote: For plotting pixels I would not use turtle graphics. That would be a fairly complicated option I'd have thought. A simple canvas would be easier. Alan G. Oh, I see! I did not realize that Tk had a canvas widget. That is nice. I will have to play with that and see if I can get everything done in the code I am working with. What I am doing is just trying to do a simple Mandelbrot set plot. It is another bit of coding that I do when learning a new language to get a handle on some of the graphics capabilities, and I am to that point. -Bill It appears that the Tk canvas widget does not support simply plotting a pixel. However, I can plot a line only one pixel long. I wonder why they do not simply provide the pixel plot primitive? I have seen very many graphics packages that do this and I have always wondered why. The primitive obviously exists in the underlying code, because that is what everything else is built upon. Does Tk actually have a something like a create_pixel method in the canvas widget that I have missed? -Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
-Original Message- From: Bill Allen <walle...@gmail.com>Sent: Sep 18, 2010 11:45 AM To: Alan Gauld <alan.ga...@btinternet.com>Cc: tutor@python.org Subject: Re: [Tutor] plotting pixels On Sat, Sep 18, 2010 at 10:44 AM, Bill Allen walle...@gmail.com wrote: On Fri, Sep 17, 2010 at 3:38 AM, Alan Gauld alan.ga...@btinternet.com wrote: For plotting pixels I would not use turtle graphics.That would be a fairly complicated option I'd have thought.A simple canvas would be easier.Alan G. Oh, I see! I did not realize that Tk had a canvas widget. That is nice. I will have to play with that and see if I can get everything done in the code I am working with. What I am doing is just trying to do a simple Mandelbrot set plot. It is another bit of coding that I do when learning a new language to get a handle on some of the graphics capabilities, and I am to that point. -Bill It appears that the Tk canvas widget does not support simply plotting a pixel. However, I can plot a line only one pixel long. I wonder why they do not simply provide the pixel plot primitive? I have seen very many graphics packages that do this and I have always wondered why. The primitive obviously exists in the underlying code, because that is what everything else is built upon. Does Tk actually have a something like a create_pixel method in the canvas widget that I have missed?-Bill Is it naive of me to ask, "Couldn't one write his own plotpixel( ) function using the line() function?" . ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
It appears that the Tk canvas widget does not support simply plotting a pixel. However, I can plot a line only one pixel long. I wonder why they do not simply provide the pixel plot primitive? I have seen very many graphics packages that do this and I have always wondered why. The primitive obviously exists in the underlying code, because that is what everything else is built upon. Does Tk actually have a something like a create_pixel method in the canvas widget that I have missed? You don't want that. Tkinter's Canvas is a Smart Canvas, each lines and shapes corresponds to a Tcl/Tk object. If you want to plot a 800*600 image pixel-per-pixel in Tkinter's Canvas, then Tkinter would have to create 48 Tcl Objects. If you want to draw pixels and lines directly, Tkinter Canvas isn't suitable for that. Try using a different Canvas, one that uses a Stateless Canvas. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Sat, Sep 18, 2010 at 1:18 PM, Ken Oliver ksterl...@mindspring.comwrote: On Fri, Sep 17, 2010 at 3:38 AM, Alan Gauld alan.ga...@btinternet.comwrote: For plotting pixels I would not use turtle graphics. That would be a fairly complicated option I'd have thought. A simple canvas would be easier. Alan G. Oh, I see! I did not realize that Tk had a canvas widget. That is nice. I will have to play with that and see if I can get everything done in the code I am working with. What I am doing is just trying to do a simple Mandelbrot set plot. It is another bit of coding that I do when learning a new language to get a handle on some of the graphics capabilities, and I am to that point. -Bill It appears that the Tk canvas widget does not support simply plotting a pixel. However, I can plot a line only one pixel long. I wonder why they do not simply provide the pixel plot primitive? I have seen very many graphics packages that do this and I have always wondered why. The primitive obviously exists in the underlying code, because that is what everything else is built upon. Does Tk actually have a something like a create_pixel method in the canvas widget that I have missed? -Bill Is it naive of me to ask, Couldn't one write his own plotpixel( ) function using the line() function? . No, not naive at all. Indeed I could, but that is not the issue in my mind. My point is that it seems strange to me that any graphics package would not make the most basic of the routines, ploting a single pixel, available. I think I actually see a way of doing it with the bitmap class, but that is not the point. While I could do exactly as you have said, I would rather either write my own low-level code to accomplish that or use a package that does provide it than to wrap up a higher end function, such as drawing a line or rectangle, into even more code in order to do less. For the particular use that I am going to put this to, a package such as pygame which does provide the ability to plot pixels directly will be more suitable. -Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
It appears that the Tk canvas widget does not support simply plotting a pixel. Correct, and I agree it seems odd, but in practice drawing either lines or ovals of one-pixel do the equivalent job - albeit a little more slowly. The primitive obviously exists in the underlying code, It probably exists in the native graphics toolkit (Xlib or Win32 or Aqua) but it doesn't exist at the Tk level which is why Tkinter can't expose it. FWIW wxPython does provide a DrawPoint() method as part of its DeviceContext class. Digging a little deeper it seems the idiomatic way to do this in Python is to use PIL the Python Imaging Library to create a GIF or bitmap image and then insert that into Tkinters cancvas as an image object. The Pil ImageDraw class has a point() ethod I've never tried this but it is described in Grayson's (now out of print?) book on Tkinter where he uses it to draw a Mandelbrot The book may be available online these days... Nowdownloadall.com seems to have it although I've no idea of the legality of it! HTH, Alan G. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
Digging a little deeper it seems the idiomatic way to do this in Python is to use PIL the Python Imaging Library to create a GIF or bitmap image and then insert that into Tkinters cancvas as an image object. The Pil ImageDraw class has a point() ethod I've never tried this but it is described in Grayson's (now out of print?) book on Tkinter where he uses it to draw a Mandelbrot The book may be available online these days... Nowdownloadall.com seems to have it although I've no idea of the legality of it! HTH, Alan G. Yes, to create a gif or a bmp from the iteration results and then to display that at the end of the run is by far the most efficient way of producing Mandelbrot and related sets. I have actually done it that way before. I just have always had a strange preference to see the set as it is being produced, which is far from efficient. Kind of a very elaborate progress bar! Anyway, I have no real complaints about the Tk canvas methods. It has always just been a pet peeve of mine when something as basic and simple as plotting a pixel is missing. My complaint on this goes way back to the ancient days when I had to figure out how to write a plot_pixel primitive in x86 assembler and then build a graphics library of my own so I could have pixel based graphics on my old monochrome IBM XT clone that had a Hercules graphics card in it. Those were the days! Mandelbrot sets in 4 shades of amber-monochrome!;-) I will check out that book you referenced. I appreciate everybody's feedback on this. -Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Sat, Sep 18, 2010 at 9:26 PM, Bill Allen walle...@gmail.com wrote:
Digging a little deeper it seems the idiomatic way to do this in Python
is to use PIL the Python Imaging Library to create a GIF or bitmap
image and then insert that into Tkinters cancvas as an image object.
The Pil ImageDraw class has a point() ethod
I've never tried this but it is described in Grayson's (now out of print?)
book on Tkinter where he uses it to draw a Mandelbrot
The book may be available online these days...
Nowdownloadall.com seems to have it although I've no idea
of the legality of it!
HTH,
Alan G.
Yes, to create a gif or a bmp from the iteration results and then to
display that at the end of the run is by far the most efficient way of
producing Mandelbrot and related sets. I have actually done it that way
before. I just have always had a strange preference to see the set as it
is being produced, which is far from efficient. Kind of a very elaborate
progress bar! Anyway, I have no real complaints about the Tk canvas
methods. It has always just been a pet peeve of mine when something as
basic and simple as plotting a pixel is missing. My complaint on this goes
way back to the ancient days when I had to figure out how to write a
plot_pixel primitive in x86 assembler and then build a graphics library of
my own so I could have pixel based graphics on my old monochrome IBM XT
clone that had a Hercules graphics card in it. Those were the days!
Mandelbrot sets in 4 shades of amber-monochrome!;-) I will check out
that book you referenced. I appreciate everybody's feedback on this.
-Bill
I found this code on the web. It creates a 100x100 tk.photoimage and
fills it with a radom colored pixels then displays it. It seems to me that
I should be able to adapt this to what I am trying to acomplish. The only
difference in the way I am filling the tk.photoimage object. I ran this
under Python 3.1.2 with success. I believe the '#%02x%02x%02x' is the
format for an image. It is a color photoimage, but I am presuming that if
written directly out to a file this would not actually produce a valid, bmp,
gif, pgn, etc. Correct? This does seem to be a reasonable solution that
is a pure Tk solution. Also it works in Python 3x, whereas the PIL library
has not yet been released for 3x. I have not mentioned it before, but
using Python 3x only is also one of my requirement, though self-imposed.
Can anyone help me better understand this part of the code below?
self.i.put('#%02x%02x%02x' % tuple(color),(row,col))
import tkinter, random
class App:
def __init__(self, t):
self.i = tkinter.PhotoImage(width=100,height=100)
colors = [[random.randint(0,255) for i in range(0,3)] for j in
range(0,1)]
row = 0; col = 0
for color in colors:
self.i.put('#%02x%02x%02x' % tuple(color),(row,col))
col += 1
if col == 100:
row +=1; col = 0
c = tkinter.Canvas(t, width=100, height=100); c.pack()
c.create_image(0, 0, image = self.i, anchor=tkinter.NW)
t = tkinter.Tk()
a = App(t)
t.mainloop()
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Re: [Tutor] plotting pixels
Bill Allen walle...@gmail.com wrote Is there a simple way to plot pixels in Python, without resorting to turtle graphics? James already mentioned matplotlib but you can just draw on a canvas. It depends on what you are trying to do. For plotting pixels I would not use turtle graphics. That would be a fairly complicated option I'd have thought. A simple canvas would be easier. Alan G. ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
[Tutor] plotting pixels
Is there a simple way to plot pixels in Python, without resorting to turtle graphics? --Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Fri, Sep 17, 2010 at 12:13 PM, Bill Allen walle...@gmail.com wrote: Is there a simple way to plot pixels in Python, without resorting to turtle graphics? Give matplotlib a go. Alternatively you may want to try pygame or pyglet. cheers James -- -- James Mills -- -- Problems are solved by method ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
Re: [Tutor] plotting pixels
On Thu, Sep 16, 2010 at 9:21 PM, James Mills prolo...@shortcircuit.net.auwrote: On Fri, Sep 17, 2010 at 12:13 PM, Bill Allen walle...@gmail.com wrote: Is there a simple way to plot pixels in Python, without resorting to turtle graphics? Give matplotlib a go. Alternatively you may want to try pygame or pyglet. cheers James -- -- James Mills -- Thanks! I'll give those a try. --Bill ___ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: http://mail.python.org/mailman/listinfo/tutor
