Re: circular markersizes via rotation matrix

[Daniel J Sebald]

On 08/19/2016 06:03 PM, Dmitri A. Sergatskov wrote:
> On Fri, Aug 19, 2016 at 4:22 PM, Rik <address@hidden
> <mailto:address@hidden>> wrote:
>
>
>     -- Benchmark # 1 --
>     N = 128;
>
>     bm = zeros (N, 1);
>     clf;
>
>     for i = 1:N
>        tic;
>        plot (1:10, "o", "markersize", N);
>        bm(i) = toc;
>     endfor
>
>     mean (bm)
>     -- End Benchmark # 1 --
>
>
> ​I tried this benchmark for "o", ".", "x", and "*" symbols and N=1280.
> All results were pretty much the same (0.0175)​. Which pretty much tells
> me that
> the most of the time spent elsewhere (not calculating the symbol shape).

Correct.  For what it's worth, here's a C program to illustrate the 
difference.  I think it is a apples-to-apples comparison, and it seems 
about right in terms of what goes into computing a sinusoidal value. 
For one million circle computations, I'm seeing:

sebald@ ~/octave/nontrig_circle_symbol $ ./testcircle
sz=12 div=3 alg=trig
real    0m1.393s
user    0m1.392s
sys     0m0.000s
sz=100 div=27 alg=trig
real    0m6.185s
user    0m6.180s
sys     0m0.000s
sz=12 div=3 alg=matrot
real    0m0.113s
user    0m0.112s
sys     0m0.000s
sz=100 div=27 alg=matrot
real    0m0.382s
user    0m0.380s
sys     0m0.000s

Dan

nontrig_circle_symbol.zip
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