The following EVAL subcommands are available:
abs absv acos aseg1 asin asp2ops atan avg avr bark2hz cdot cepstrum cget cmul conj corr corrfun cos cp2r cr2len cr2phi cset ctrn dB dct dev dft dist e erb2hz exp f0ac fft fill fir1 floor formants grand haclust hist hth hz2bark hz2erb hz2mel ifft iir1 iir2 imax imin init int interp ipeak ld limit limithigh limitlow lin2log ln log log2lin lpc max median mel2hz min nrow pi qdet qinterp rand round rpoly rpolyreg select sig2osp sign sin sinx smooth sqrt stddev sum tan ticks2f1 trn var vmcol vmrow vsubc vsubn vv vvcat vvget vvset wbartlett wblackman wflattop wgauss whamming whanning window wkaiser wnuttall wsum wtaprect ydiff yint zcross