librelist archives

Re: [flask]using matplotlib to render data to webpage directly

From:

刘一新

Date:

2011-09-29 @ 09:23

Thanks, Simon

Few minutes ago, I figured out the same method as your first one by reading
a article on web2py and matplotlib (Di Pierro, M. "Web2Py for Scientific
Applications" Comput. Sci. Eng. 2011, 64.)

BTW: If the data I want to plot is changing, is there any way to refresh the
image I just rendered? I think this is similar to play a streaming vedio.

Eshin

2011/9/29 Simon Sapin <simon.sapin@exyr.org>

>  On Thu, 29 Sep 2011 16:43:21 +0800, 刘一新 wrote:
> > Hi, everyone.
> > I want to plot some data on the webpage directly on the webpage
> > without saving the graph as a file. By google search, I found a
> > solution here: https://gist.github.com/862153 [1]. However, this
> > solution directly render the data in a single webpage. I want to
> > render the data as part of a webpage, which is much like a  tag.
> > Then,
> > I can add more things to that page. What  should I do?
> > Thanks.
> >
>
>  Hi,
>
>  The example you gives serves the plot as a signle PNG file at a given
>  URL. You can then include it in an HTML page with <img src="{{ that_url
>  }}>. Of course if the data is not always the same, you may want to have
>  some parameters in the URL. The image is not saved in a file, but it is
>  created in a different HTTP request than the HTML.
>
>  If you really want to create the plot and the HTML content in the same
>  HTTP request, you can encode the PNG data in base64 and include it in
>  the HTML with a "data:" URL.
>  See http://en.wikipedia.org/wiki/Data_URI_scheme (there is a Python
>  exemple there too)
>
>  Regards,
> --
>  Simon Sapin
>



-- 
*Dr. Yi-Xin Liu*
*Department of Macromolecular Science*
*Fudan University*
*Room 415, Yuejing Building *
*Handan Rd. 220, **Shanghai, China*
*Tel +86-021-65642863*
*Mobile +86-13916819745*
http://www.mendeley.com/profiles/yi-xin-liu/

 On Thu, 29 Sep 2011 17:23:30 +0800, 刘一新 wrote:
> Thanks, Simon
>
> Few minutes ago, I figured out the same method as your first one by
> reading a article on web2py and matplotlib (Di Pierro, M. "Web2Py for
> Scientific Applications" Comput. Sci. Eng. 2011, 64.)
>
> BTW: If the data I want to plot is changing, is there any way to
> refresh the image I just rendered? I think this is similar to play a
> streaming vedio.
>
> Eshin

 Hi,

 If you want to reload an image without reloading the whole page, try 
 something like this:

     my_image.src = my_image.src;

 in Javascript, with my_image being a DOM element.

 Regards,
-- 
 Simon Sapin