[Liguid-dsp][1] implements root-Nyquist harris-Moerder (hM-3) filter using Parks-McClellan algorithm as : 

```c
void [liquid_firdes_hM3][2](unsigned int _k,
                            unsigned int _m,
                            float _beta,
                            float _dt,
                            float * _h) 
```
  [1]: https://github.com/jgaeddert/liquid-dsp
  [2]: https://github.com/jgaeddert/liquid-dsp/blob/master/src/filter/src/hM3.c