'weights' must all be finite

Hi!

Sadly I can’t seem to get trendsceek to run on my data. I get:

```r
> trendstat_list <- trendsceek_test(pp2plot, nrand = 10, ncores = 1)
Error in density.default(d, weights = fw/sum.fw, from = min(rvals), to = max(rvals), : 'weights' must all be finite
```

It’s also very slow, but when I set nrand lower, it crashes with another error.