''' Created on 6. okt. 2016 @author: pab ''' from __future__ import absolute_import, division from numba import jit, float64, int64, int32, int8, void import numpy as np @jit(void(int64, int64, int64, int64[:], int8[:], int64, int64)) def _find_first_cross(ix, start, dcross, ind, y, v, n): if y[0] < v: dcross = -1 # first is a up-crossing elif y[0] > v: dcross = 1 # first is a down-crossing elif y[0] == v: # Find out what type of crossing we have next time.. for i in range(1, n): start = i if y[i] < v: ind[ix] = i - 1 # first crossing is a down crossing ix += 1 dcross = -1 # The next crossing is a up-crossing break elif y[i] > v: ind[ix] = i - 1 # first crossing is a up-crossing ix += 1 dcross = 1 # The next crossing is a down-crossing break @jit(int64(int64[:], int8[:])) def _findcross(ind, y): ix, dcross, start, v = 0, 0, 0, 0 n = len(y) _find_first_cross(ix, start, dcross, ind, y, v, n) for i in range(start, n - 1): if ((dcross == -1 and y[i] <= v and v < y[i + 1]) or (dcross == 1 and v <= y[i] and y[i + 1] < v)): ind[ix] = i ix += 1 dcross = -dcross return ix def findcross(xn): '''Return indices to zero up and downcrossings of a vector ''' ind = np.empty(len(xn), dtype=np.int64) m = _findcross(ind, xn) return ind[:m] def _make_findrfc(cmp1, cmp2): @jit(int64(int64[:], float64[:], float64), nopython=True) def local_findrfc(t, y, h): # cmp1, cmp2 = (a_le_b, a_lt_b) if method==0 else (a_lt_b, a_le_b) n = len(y) j, t0, z0 = 0, 0, 0 y0 = y[t0] # The rainflow filter for ti in range(1, n): fpi = y0 + h fmi = y0 - h yi = y[ti] if z0 == 0: if cmp1(yi, fmi): z1 = -1 elif cmp1(fpi, yi): z1 = +1 else: z1 = 0 t1, y1 = (t0, y0) if z1 == 0 else (ti, yi) else: if (((z0 == +1) and cmp1(yi, fmi)) or ((z0 == -1) and cmp2(yi, fpi))): z1 = -1 elif (((z0 == +1) and cmp2(fmi, yi)) or ((z0 == -1) and cmp1(fpi, yi))): z1 = +1 else: raise ValueError # warnings.warn('Something wrong, i={}'.format(tim1)) # Update y1 if z1 != z0: t1, y1 = ti, yi elif z1 == -1: t1, y1 = (t0, y0) if y0 < yi else (ti, yi) elif z1 == +1: t1, y1 = (t0, y0) if y0 > yi else (ti, yi) # Update y if y0 is a turning point if abs(z0 - z1) == 2: j += 1 t[j] = t0 # Update t0, y0, z0 t0, y0, z0 = t1, y1, z1 # end # Update y if last y0 is greater than (or equal) threshold if cmp2(h, abs(y0 - y[t[j]])): j += 1 t[j] = t0 return j + 1 return local_findrfc @jit(int32(float64, float64), nopython=True) def a_le_b(a, b): return a <= b @jit(int32(float64, float64), nopython=True) def a_lt_b(a, b): return a < b _findrfc_le = _make_findrfc(a_le_b, a_lt_b) _findrfc_lt = _make_findrfc(a_lt_b, a_le_b) @jit(int64(int64[:], float64[:], float64), nopython=True) def _findrfc(ind, y, h): n = len(y) t_start = 0 NC = n // 2 - 1 ix = 0 for i in range(NC): Tmi = t_start + 2 * i Tpl = t_start + 2 * i + 2 xminus = y[2 * i] xplus = y[2 * i + 2] if(i != 0): j = i - 1 while ((j >= 0) and (y[2 * j + 1] <= y[2 * i + 1])): if (y[2 * j] < xminus): xminus = y[2 * j] Tmi = t_start + 2 * j j -= 1 if (xminus >= xplus): if (y[2 * i + 1] - xminus >= h): ind[ix] = Tmi ix += 1 ind[ix] = (t_start + 2 * i + 1) ix += 1 # goto L180 continue else: j = i + 1 while (j < NC): if (y[2 * j + 1] >= y[2 * i + 1]): break # goto L170 if((y[2 * j + 2] <= xplus)): xplus = y[2 * j + 2] Tpl = (t_start + 2 * j + 2) j += 1 else: if ((y[2 * i + 1] - xminus) >= h): ind[ix] = Tmi ix += 1 ind[ix] = (t_start + 2 * i + 1) ix += 1 # iy = i continue # goto L180 # L170: if (xplus <= xminus): if ((y[2 * i + 1] - xminus) >= h): ind[ix] = Tmi ix += 1 ind[ix] = (t_start + 2 * i + 1) ix += 1 elif ((y[2 * i + 1] - xplus) >= h): ind[ix] = (t_start + 2 * i + 1) ix += 1 ind[ix] = Tpl ix += 1 # L180: # iy=i # /* for i */ return ix def findrfc(y, h, method=0): n = len(y) t = np.zeros(n, dtype=np.int64) findrfc_ = [_findrfc_le, _findrfc_lt, _findrfc][method] m = findrfc_(t, y, h) return t[:m] @jit(void(float64[:], float64[:], float64[:], float64[:], float64[:], float64[:], float64, float64, int32, int32, int32, int32), nopython=True) def _finite_water_disufq(rvec, ivec, rA, iA, w, kw, h, g, nmin, nmax, m, n): # kfact is set to 2 in order to exploit the symmetry. # If you set kfact to 1, you must uncomment all statements # including the expressions: rvec[iz2], rvec[iv2], ivec[iz2] and ivec[iv2]. kfact = 2.0 for ix in range(nmin - 1, nmax): # for (ix = nmin-1;ix=0) kw = vector with wavenumbers (kw>=0) h = water depth (h >=0) g = constant acceleration of gravity nmin = minimum index where rA(:,nmin) and iA(:,nmin) is greater than zero. nmax = maximum index where rA(:,nmax) and iA(:,nmax) is greater than zero. m = size(rA,1),size(iA,1) n = size(rA,2),size(iA,2), or size(rvec,2),size(ivec,2) returns ------- rvec, ivec = real and imaginary parts of the resultant (size m X n). DISUFQ returns the summation of difference frequency and sum frequency effects in the vector vec = rvec +sqrt(-1)*ivec. The 2'nd order contribution to the Stokes wave is then calculated by a simple 1D Fourier transform, real(FFT(vec)). """ rvec = np.zeros(n * m) ivec = np.zeros(n * m) if h > 10000: # { /* deep water /Inifinite water depth */ _deep_water_disufq(rvec, ivec, rA, iA, w, kw, h, g, nmin, nmax, m, n) else: _finite_water_disufq(rvec, ivec, rA, iA, w, kw, h, g, nmin, nmax, m, n) return rvec, ivec @jit(int32[:](float64[:], float64[:], float64[:, :])) def _findrfc3_astm(array_ext, a, array_out): """ Rain flow without time analysis Return [ampl ampl_mean nr_of_cycle] By Adam Nieslony Visit the MATLAB Central File Exchange for latest version http://www.mathworks.com/matlabcentral/fileexchange/3026 """ n = len(array_ext) po = 0 # The original rainflow counting by Nieslony, unchanged j = -1 c_nr1 = 1 for i in range(n): j += 1 a[j] = array_ext[i] while j >= 2 and abs(a[j - 1] - a[j - 2]) <= abs(a[j] - a[j - 1]): ampl = abs((a[j - 1] - a[j - 2]) / 2) mean = (a[j - 1] + a[j - 2]) / 2 if j == 2: a[0] = a[1] a[1] = a[2] j = 1 if (ampl > 0): array_out[po, :] = (ampl, mean, 0.5) po += 1 else: a[j - 2] = a[j] j = j - 2 if (ampl > 0): array_out[po, :] = (ampl, mean, 1.0) po += 1 c_nr1 += 1 c_nr2 = 1 for i in range(j): ampl = abs(a[i] - a[i + 1]) / 2 mean = (a[i] + a[i + 1]) / 2 if (ampl > 0): array_out[po, :] = (ampl, mean, 0.5) po += 1 c_nr2 += 1 return c_nr1, c_nr2 @jit(int32[:](float64[:], float64[:], float64[:], float64[:], float64[:, :])) def _findrfc5_astm(array_ext, array_t, a, t, array_out): """ Rain flow with time analysis returns [ampl ampl_mean nr_of_cycle cycle_begin_time cycle_period_time] By Adam Nieslony Visit the MATLAB Central File Exchange for latest version http://www.mathworks.com/matlabcentral/fileexchange/3026 """ n = len(array_ext) po = 0 # The original rainflow counting by Nieslony, unchanged j = -1 c_nr1 = 1 for i in range(n): j += 1 a[j] = array_ext[i] t[j] = array_t[i] while (j >= 2) and (abs(a[j - 1] - a[j - 2]) <= abs(a[j] - a[j - 1])): ampl = abs((a[j - 1] - a[j - 2]) / 2) mean = (a[j - 1] + a[j - 2]) / 2 period = (t[j - 1] - t[j - 2]) * 2 atime = t[j - 2] if j == 2: a[0] = a[1] a[1] = a[2] t[0] = t[1] t[1] = t[2] j = 1 if (ampl > 0): array_out[po, :] = (ampl, mean, 0.5, atime, period) po += 1 else: a[j - 2] = a[j] t[j - 2] = t[j] j = j - 2 if (ampl > 0): array_out[po, :] = (ampl, mean, 1.0, atime, period) po += 1 c_nr1 += 1 c_nr2 = 1 for i in range(j): # for (i=0; i 0): array_out[po, :] = (ampl, mean, 0.5, atime, period) po += 1 c_nr2 += 1 return c_nr1, c_nr2 def findrfc_astm(tp, t=None): """ Return rainflow counted cycles Nieslony's Matlab implementation of the ASTM standard practice for rainflow counting ported to a Python C module. Parameters ---------- tp : array-like vector of turningpoints (NB! Only values, not sampled times) t : array-like vector of sampled times Returns ------- sig_rfc : array-like array of shape (n,3) or (n, 5) with: sig_rfc[:,0] Cycles amplitude sig_rfc[:,1] Cycles mean value sig_rfc[:,2] Cycle type, half (=0.5) or full (=1.0) sig_rfc[:,3] cycle_begin_time (only if t is given) sig_rfc[:,4] cycle_period_time (only if t is given) """ y1 = np.atleast_1d(tp).ravel() n = len(y1) a = np.zeros(n) if t is None: sig_rfc = np.zeros((n, 3)) cnr = _findrfc3_astm(y1, a, sig_rfc) else: t1 = np.atleast_1d(t).ravel() sig_rfc = np.zeros((n, 5)) t2 = np.zeros(n) cnr = _findrfc5_astm(y1, t1, a, t2, sig_rfc) # the sig_rfc was constructed too big in rainflow.rf3, so # reduce the sig_rfc array as done originally by a matlab mex c function # n = len(sig_rfc) return sig_rfc[:n - cnr[0]] if __name__ == '__main__': pass