Re: [Gnuplot-info] How to plot directly in unit of pixels by gnuplot?

[Fayer M. <fay...@gm...>]

Yes, I have to, because I want to see pixels clearly.

I found 'digest' in the mailing list is slow. Maybe I shouldn't use this feature? I worry if I choose 'no' in 'Would you like to receive list mail batched in a daily digest', I will get nothing any more. I'm a newbie. Sorry for such questions.

Fayer

> Date: Wed, 21 Jul 2010 05:08:01 -0700 (PDT)
> From: Thomas Sefzick <t.s...@fz...>
> Subject: Re: [Gnuplot-info] How to plot directly in unit of pixels by
> gnuplot?
> To: gnu...@li...
> Message-ID: <292...@ta...>
> Content-Type: text/plain; charset=us-ascii
> 
> 
> did you deactivate the 'Smooth images when zoomed' feature in 'eog'?
> 
> 
> Fayer Michael wrote:
>> 
>> That's exactly what I have tried and failed. What I really want to draw
>> is thousands of thin (big width, small height) rectangles without
>> overlapping but connected (no space between them vertically, but can
>> have space horizontally). They are in different colors and have
>> different width. If I use this kind of relative coordinates (eg.
>> 100/640), the rectangles will overlap vertically a little bit (see code
>> below). That's why I wonder if any methods can use absolute coordinates
>> in pixels to avoid overlapping.
>> 
>> The code:
>> 
>> set cbrange [0:6]
>> set style rect fs solid noborder
>> set xrange [0:1]
>> set yrange [0:1]
>> set key off
>> unset xtics
>> unset ytics
>> unset colorbox
>> set palette defined (0 "black",1 "yellow")
>> set tmargin 0
>> set lmargin 0
>> set bmargin 0
>> set rmargin 0
>> set terminal png size 10,10
>> set output "tt.png"
>> set obj rect from 0,0 to 0.5,0.5 fc palette cb 3
>> set obj rect from 1,1 to 0.5,0.5 fc palette cb 6
>> plot -1 lc palette cb 1 # invisible, to show content above
>> replot
>> 
>> By using 'eog', one can zoom in the png file up to 2000%, and see two
>> rectangles are overlapped (although mathmetically they should not
>> overlap) and the edges/frames also are not 'tidy'.
>> 
>>> Date: Tue, 20 Jul 2010 10:32:23 -0700 (PDT)
>>> From: Thomas Sefzick <t.s...@fz...>
>>> Subject: Re: [Gnuplot-info] How to plot directly in unit of pixels by
>>> gnuplot?
>>> To: gnu...@li...
>>> Message-ID: <292...@ta...>
>>> Content-Type: text/plain; charset=us-ascii
>>> 
>>> 
>>> use the screen coordinates when defining objects:
>>> 
>>> set term gif size 640,480
>>> set obj 1 rect from screen 100./640.,20./480. to screen
>>> 200./640.,30./480.
>>> fc palette cb 3
>>> set out 'plot.gif'
>>> plot sin(x)
>>> set out
>>> 
>>> 
>>> Fayer Michael wrote:
>>> > 
>>> > Except for canvas size, gnuplot uses relative unit to plot. Now I want
>>> > to draw directly in unit of pixels. For example, I want something like:
>>> >   set obj rect from 100,20 to 200,30 fc palette cb 3
>>> > 
>>> > where 100,20 and 200,30 are in pixel.
>>> > 
>>> > I set xrange/yrange to something like 1:640 and 1:480, and set all
>>> > margins to 0. However, the results were still not exactly what I want.
>>> > And it's a dirty hack. Anyone knows a clean one?
>>> > 
>>> > I noticed low-level Perl package Term::Gnuplot, but it's not convenient
>>> > for high-level plotting.
>>> > 
>>> > Fayer