Re: [Matplotlib-users] dashes and dpi?

 Re: [Matplotlib-users] dashes and dpi? From: Alan G Isaac - 2008-02-01 09:16:20 ```On Fri, 1 Feb 2008, Mark Bakker apparently wrote: > you claim that 1pt = 1/72 inch. Is that always the case? > And why? How does mpl figure that out Based on the discussion for far, I assume it works like this. (figsize in inches) * dpi = (size in pixels) So if you draw a line 72 points long, which is 1" in figsize units, then it will display as being dpi pixels in length. So for PNG, for example, figsize is a kind of Platonic concept, which we view dimly through the actual size of our figure. By the way, I've discovered that browser scaling of PNGs does not work very well (fuzzy fonts), so setting both figsize and dpi correctly proves rather important. In contrast to best practice for loading speed, you should not set the size of your IMG element. Or so it seems. fwiw, Alan ```

 [Matplotlib-users] dashes and dpi? From: Mark Bakker - 2008-02-01 08:42:41 Attachments: Message as HTML ```Alan - You started a discussion about dpi on the figures. Yet here you claim that 1pt = 1/72 inch. Is that always the case? And why? How does mpl figure that out, if there are also different dpi settings? The plot thickens... Mark > Alan Isaac wrote: > Note: 1pt = 1/72 inch > > hth, > Alan Isaac > ```
 Re: [Matplotlib-users] dashes and dpi? From: Manuel Metz - 2008-02-01 09:02:18 ```Mark Bakker wrote: > Alan - > > You started a discussion about dpi on the figures. > Yet here you claim that 1pt = 1/72 inch. > Is that always the case? Yes, I that's *by definition* always the case ! pt is a point - not a dot or a pixel !!! "Point" is a unit of measurement used in typography that is equal to 1/72 inch. It is used primarily for representing the height of characters and the amount of space between lines, also known as leading. --> see http://support.microsoft.com/kb/76388 Manuel > And why? How does mpl figure that out, if there are also different dpi > settings? > The plot thickens... > > Mark > > >> Alan Isaac wrote: > > >> Note: 1pt = 1/72 inch >> >> hth, >> Alan Isaac >> > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > > ------------------------------------------------------------------------ > > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@... > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ```
 Re: [Matplotlib-users] dashes and dpi? From: Alan G Isaac - 2008-02-01 09:16:20 ```On Fri, 1 Feb 2008, Mark Bakker apparently wrote: > you claim that 1pt = 1/72 inch. Is that always the case? > And why? How does mpl figure that out Based on the discussion for far, I assume it works like this. (figsize in inches) * dpi = (size in pixels) So if you draw a line 72 points long, which is 1" in figsize units, then it will display as being dpi pixels in length. So for PNG, for example, figsize is a kind of Platonic concept, which we view dimly through the actual size of our figure. By the way, I've discovered that browser scaling of PNGs does not work very well (fuzzy fonts), so setting both figsize and dpi correctly proves rather important. In contrast to best practice for loading speed, you should not set the size of your IMG element. Or so it seems. fwiw, Alan ```
 Re: [Matplotlib-users] dashes and dpi? From: Michael Droettboom - 2008-02-01 13:19:26 ```Mark Bakker wrote: > Alan - > > You started a discussion about dpi on the figures. > Yet here you claim that 1pt = 1/72 inch. > Is that always the case? Barring any bugs, yes. > And why? How does mpl figure that out, if there are also different dpi > settings? The conversion from points to pixels is simply "dpi * points / 72.0". Cheers, Mike > The plot thickens... > > Mark > > > Alan Isaac wrote: > > > Note: 1pt = 1/72 inch > > hth, > Alan Isaac > > > > ------------------------------------------------------------------------ > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Microsoft > Defy all challenges. Microsoft(R) Visual Studio 2008. > http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ > > > ------------------------------------------------------------------------ > > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@... > https://lists.sourceforge.net/lists/listinfo/matplotlib-users -- Michael Droettboom Science Software Branch Operations and Engineering Division Space Telescope Science Institute Operated by AURA for NASA ```
 Re: [Matplotlib-users] dashes and dpi? From: Christopher Barker - 2008-02-01 18:02:51 ``` Alan G Isaac wrote: > On Fri, 1 Feb 2008, Mark Bakker apparently wrote: >> you claim that 1pt = 1/72 inch. Is that always the case? >> And why? How does mpl figure that out I wrote this to help clarify some of these issues: http://www.scipy.org/Cookbook/Matplotlib/AdjustingImageSize > By the way, I've discovered that browser scaling > of PNGs does not work very well (fuzzy fonts), right, scaling rasters is never optimum. > so > setting both figsize and dpi correctly proves > rather important. exactly. > In contrast to best practice > for loading speed, you should not set the size > of your IMG element. you can set it, but make sure it matches the actual image size. That will get you the rendering speed, with no quality penalty. -Chris -- Christopher Barker, Ph.D. Oceanographer Emergency Response Division NOAA/NOS/OR&R (206) 526-6959 voice 7600 Sand Point Way NE (206) 526-6329 fax Seattle, WA 98115 (206) 526-6317 main reception Chris.Barker@... ```
 Re: [Matplotlib-users] dashes and dpi? From: Wayne E. Harlan - 2008-02-02 18:30:41 ``` Mark Bakker wrote: > Yet here you claim that 1pt = 1/72 inch. > Is that always the case? Kind of. This is a typesetting measurement originally having nothing to do with computers, displays or graphics files. However at Wikipedia they say its definition has changed over time. http://en.wikipedia.org/wiki/Point_%28typography%29 ```