Re: Speeding Up gnuplot Interface with Binary Data

[John W. Eaton]

On  7-Oct-2008, Daniel J Sebald wrote:

| John W. Eaton wrote:
| > On  7-Oct-2008, Daniel J Sebald wrote:
| > 
| > | John,
| > | 
| > | Attached is a patch using gnuplot's binary data input feature rather than 
ASCII data fifteen characters wide.  It does appear to speed up drawing a fair 
amount.  Less data is transmitted through the pipe, gnuplot doesn't have to 
input data as formated, and as I see it there is no need for handling NaN in a 
special way (it is just another value in IEEE format).
| > | 
| > | Let me know what you think.
| > 
| > This patch fails to apply cleanly to the current Octave sources.
| 
| Sorry.  I'm out of step with Mercurial.  Give this patch a try...

OK, this applies cleanly to my sources.

| +    fwrite (plot_stream, data, "float32");

Why float32?  That breaks things like

  plot ([1, 2], [3, 4]*1e100)

which used to work properly.  I think we should be sending double
precision data.

jwe