Programmer Guide/Command Reference/EVAL/ticks2f1

Extracts the rps (= the number of rotations per second) value or track from the tick-signal x.

---

Usage

ticks2f1(x, sr, o {, l, s})

x

the tick signal vector

sr

sampling rate of the tick signal in Hz

type

the order of the tick signal

Description

The function counts the periods of the tick signal and computes the rps value according to the sampling rate sr and the order of the tick signal o. The tick signal x must be a periodic signal (sine wave, triangle, rectangle, sawtooth or pulse) with o periods per rotation.

rps = sr / o * np / (ilast-ifirst)

with:

np

number of detected periodes

ifirst

sample index of the begin of the first periode

ilast

sample index of the end of the last periode smoothed value xs[i] is computed from the data values x[i-m] to x[i+m]. The general form of the smoothing function is: x s [ i ] = ∑ j = − m m x [ i + j ] . w [ j ] ∑ j = − m m w [ j ] {\displaystyle xs[i]={\frac {\sum _{j=-m}^{m}{x[i+j].w[j]}}{\sum _{j=-m}^{m}{w[j]}}}} $xs[i]={\frac {\sum _{j=-m}^{m}{x[i+j].w[j]}}{\sum _{j=-m}^{m}{w[j]}}}$ The weighting coefficients w[i] depend on the value of the argument type type w[j] 0 1 average 1 1 / (|j|+1) distance weighted average Result A vector r with nrow(x)/s elements. The value r[j] is set to the value xs[j*s] of the smoothed data vector. ticks2f1 Usage: ticks2f1(x, sr, xo {, lfrm, sfrm}) Function: Extracts the rpm value/track (rpm = the number of rotations per second) from the tick-signal x. Parameters: x The tick signal. sr The sampling rate of x. xo The order of the tick signal. lfrm The frame length. The default is nrow(x). sfrm The frame shift. The default is the value of lfrm. Result: The rpm value or track (a number or a vector). Notes: See also optmm <function list>