Re: [Plplot-general] plot to RGBA string ?

[Alan W. I. <Ala...@gm...>]

On 2019-09-04 21:42-0400 Hazen Babcock wrote:

>
>
> On 9/4/19 8:10 PM, Alan W. Irwin wrote:
>> On 2019-09-04 21:32+0200 Xavier Cardil wrote:
>> 
>>> Hi, we are using Plplot on a project with Keras, where we are required to
>>> feed plots as RGBA encoded string plot. Is it possible to do this somehow 
>>> ?
>>> 
>>> I have read about plsmema( )
>>> 
>>> http://plplot.sourceforge.net/docbook-manual/plplot-html-5.15.0/plsmema.html 
>>> 
>>> But this looks to be a way to input, not to output ?
>> 
>> Hi Xavier:
>> 
>> Yes, plsmema is input so I don't think it is suitable for your described 
>> needs.
>
> Sorry it isn't clear to me what is meant by input here, so I will plow ahead. 
> The function plsmema sets the memory space for the memcairo to use when 
> plotting. So it is input in the sense that you pass it a pointer to the 
> memory where you want the plot rendered. But it is also output in the sense 
> that the memcairo drive will fill this memory with the plot image. If you 
> then saved this block of memory as an (RGBA) image you would see the plot. If 
> you are looking to pass pictures of plots to Keras then might be what you are 
> looking for.
>
> Though not a "official example", there is a Python example that uses this 
> function:
>
> plplot/examples/python/test_plsmem.py.in

To Hazen and Xavier:

@Hazen: Good points which have convinced me I should not have dismissed plsmema quite so quickly.  In fact, we can
make no judgement about any of this until we know the exact needs of Keras.

@Xavier: To help us understand those needs, what is exact format of
what you call an "RGBA encoded string plot"?  I have asked for this
clarification because if you search for "RGBA encoded string" with
those quotes there are only two (java) google hits.  And there are no
google hits at all for "RGBA encoded string plot" with those quotes.

Alan

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Alan W. Irwin

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