on.<br />
<br />
 Sampling a simulation writes out the mutation frequencies from the GPU's memory vRAM to the CPU's RAM for storage and later analysis. Sampling a simulation at a time point other than the final generation (the final generation is always sampled) will also trigger the preserve flag (and thus compact if <code>compact_interval &gt; 0</code>). Thus, those mutations sampled at generation <code>t</code> will be preserved in all samples after generation <code>t</code> in order to ease frequency co