Added more test to test/test_misc.py and test/test_gaussian.py

master
Per.Andreas.Brodtkorb 15 years ago
parent 3623d76102
commit e2793d38c7

@ -1,9 +1,12 @@
import warnings
import numpy as np
from numpy import (r_, minimum, maximum, atleast_1d, atleast_2d, mod, zeros, #@UnresolvedImport
ones, floor, random, eye, nonzero, repeat, sqrt, inf, diag, triu) #@UnresolvedImport
ones, floor, random, eye, nonzero, repeat, sqrt, exp, inf, diag, triu) #@UnresolvedImport
from scipy.special import ndtri as invnorm
from scipy.special import ndtr as cdfnorm
import wafo.rindmod as rindmod
import wafo.mvnprdmod as mvnprdmod
from wafo import mvn
class Rind(object):
'''
@ -68,7 +71,7 @@ class Rind(object):
>>> m = np.zeros(n); rho = 0.3;
>>> Sc =(np.ones((n,n))-np.eye(n))*rho+np.eye(n)
>>> rind = Rind()
>>> E0 = rind(Sc,m,Blo,Bup,indI) # exact prob. 0.001946
>>> E0, err0, terr0 = rind(Sc,m,Blo,Bup,indI) # exact prob. 0.001946
>>> A = np.repeat(Blo,n); B = np.repeat(Bup,n) # Integration limits
>>> E1 = rind(np.triu(Sc),m,A,B) #same as E0
@ -358,6 +361,334 @@ def test_rind():
Blo[0, ind] = maximum(Blo[0, ind], -infinity * dev[indI[ind + 1]])
E3 = rind(Sc, m, Blo, Bup, indI, xc, nt=1)
def cdflomax(x,alpha,m0):
'''
Return CDF for local maxima for a zero-mean Gaussian process
Parameters
----------
x : array-like
evaluation points
alpha, m0 : real scalars
irregularity factor and zero-order spectral moment (variance of the
process), respectively.
Returns
-------
prb : ndarray
distribution function evaluated at x
Notes
-----
The cdf is calculated from an explicit expression involving the
standard-normal cdf. This relation is sometimes written as a convolution
M = sqrt(m0)*( sqrt(1-a^2)*Z + a*R )
where M denotes local maximum, Z is a standard normal r.v.,
R is a standard Rayleigh r.v., and "=" means equality in distribution.
Note that all local maxima of the process are considered, not
only crests of waves.
Example
-------
>>> pylab
>>> import wafo.spectrum.models as wsm
>>> import wafo.objects as wo
>>> import wafo.stats as ws
>>> S = wsm.Jonswap(Hm0=10).tospecdata();
>>> xs = S.sim(10000)
>>> ts = wo.mat2timeseries(xs)
>>> tp = ts.turning_points()
>>> mM = tp.cycle_pairs()
>>> m0 = S.moment(1)[0]
>>> alpha = S.characteristic('alpha')[0]
>>> x = linspace(-10,10,200);
>>> mcdf = ws.edf(mM.data)
>>> mcdf.plot(), pylab.plot(x,cdflomax(x,alpha,m0))
See also
--------
spec2mom, spec2bw
'''
c1 = 1.0/(sqrt(1-alpha**2))*x/sqrt(m0)
c2 = alpha*c1
return cdfnorm(c1)-alpha*exp(-x**2/2/m0)*cdfnorm(c2)
def prbnormtndpc(rho,a,b,D=None,df=0,abseps=1e-4,IERC=0,HNC=0.24):
'''
Return Multivariate normal or T probability with product correlation structure.
Parameters
----------
rho : array-like
vector of coefficients defining the correlation coefficient by:
correlation(I,J) = rho[i]*rho[j]) for J!=I
where -1 < rho[i] < 1
a,b : array-like
vector of lower and upper integration limits, respectively.
Note: any values greater the 37 in magnitude, are considered as infinite values.
D : array-like
vector of means (default zeros(size(rho)))
df = Degrees of freedom, NDF<=0 gives normal probabilities (default)
abseps = absolute error tolerance. (default 1e-4)
IERC = 1 if strict error control based on fourth derivative
0 if intuitive error control based on halving the intervals (default)
HNC = start interval width of simpson rule (default 0.24)
Returns
-------
value = estimated value for the integral
bound = bound on the error of the approximation
inform = INTEGER, termination status parameter:
0, if normal completion with ERROR < EPS;
1, if N > 1000 or N < 1.
2, IF any abs(rho)>=1
4, if ANY(b(I)<=A(i))
5, if number of terms computed exceeds maximum number of evaluation points
6, if fault accurs in normal subroutines
7, if subintervals are too narrow or too many
8, if bounds exceeds abseps
PRBNORMTNDPC calculates multivariate normal or student T probability
with product correlation structure for rectangular regions.
The accuracy is as best around single precision, i.e., about 1e-7.
Example:
--------
>>> rho2 = np.random.rand(2);
>>> a2 = np.zeros(2);
>>> b2 = np.repeat(np.inf,2);
>>> [val2,err2, ift2] = prbnormtndpc(rho2,a2,b2)
>>> g2 = lambda x : 0.25+np.arcsin(x[0]*x[1])/(2*pi)
>>> E2 = g2(rho2) #% exact value
>>> np.abs(E2-val2)<err2
True
>>> rho3 = np.random.rand(3)
>>> a3 = np.zeros(3)
>>> b3 = np.repeat(inf,3)
>>> [val3,err3, ift3] = prbnormtndpc(rho3,a3,b3)
>>> g3 = lambda x : 0.5-sum(np.sort(np.arccos([x[0]*x[1],x[0]*x[2],x[1]*x[2]])))/(4*pi)
>>> E3 = g3(rho3) # Exact value
>>> np.abs(E3-val3)<err2
True
See also
--------
prbnormndpc, prbnormnd, rind
Reference
---------
Charles Dunnett (1989)
"Multivariate normal probability integrals with product correlation
structure", Applied statistics, Vol 38,No3, (Algorithm AS 251)
'''
if D is None:
D = zeros(len(rho))
# Make sure integration limits are finite
A = np.clip(a-D,-100,100)
B = np.clip(b-D,-100,100)
return mvnprdmod.prbnormtndpc(rho,A,B,df,abseps,IERC,HNC)
def prbnormndpc(rho,a,b,abserr=1e-4,relerr=1e-4,usesimpson=True, usebreakpoints=False):
'''
Return Multivariate Normal probabilities with product correlation
Parameters
----------
rho = vector defining the correlation structure, i.e.,
corr(Xi,Xj) = rho(i)*rho(j) for i~=j
= 1 for i==j
-1 <= rho <= 1
a,b = lower and upper integration limits respectively.
tol = requested absolute tolerance
Returns
-------
value = value of integral
error = estimated absolute error
PRBNORMNDPC calculates multivariate normal probability
with product correlation structure for rectangular regions.
The accuracy is up to almost double precision, i.e., about 1e-14.
Example:
-------
>>> rho2 = np.random.rand(2);
>>> a2 = np.zeros(2);
>>> b2 = np.repeat(np.inf,2);
>>> [val2,err2, ift2] = prbnormndpc(rho2,a2,b2)
>>> g2 = lambda x : 0.25+np.arcsin(x[0]*x[1])/(2*pi)
>>> E2 = g2(rho2) #% exact value
>>> np.abs(E2-val2)<err2
True
>>> rho3 = np.random.rand(3)
>>> a3 = np.zeros(3)
>>> b3 = np.repeat(inf,3)
>>> [val3,err3, ift3] = prbnormndpc(rho3,a3,b3)
>>> g3 = lambda x : 0.5-sum(np.sort(np.arccos([x[0]*x[1],x[0]*x[2],x[1]*x[2]])))/(4*pi)
>>> E3 = g3(rho3) # Exact value
>>> np.abs(E3-val3)<err2
True
See also
--------
prbnormtndpc, prbnormnd, rind
Reference
---------
P. A. Brodtkorb (2004),
"Evaluating multinormal probabilites with product correlation structure."
In Lund university report series
and in the Dr.Ing thesis:
"The probability of Occurrence of dangerous Wave Situations at Sea."
Dr.Ing thesis, Norwegian University of Science and Technolgy, NTNU,
Trondheim, Norway.
'''
# Call fortran implementation
val,err,ier = mvnprdmod.prbnormndpc(rho,a,b,abserr,relerr,usebreakpoints,usesimpson);
if ier>0:
warnings.warn('Abnormal termination ier = %d\n\n%s' % (ier,_ERRORMESSAGE[ier]))
return val, err, ier
_ERRORMESSAGE = {}
_ERRORMESSAGE[0] = ''
_ERRORMESSAGE[1] ='''
Maximum number of subdivisions allowed has been achieved. one can allow
more subdivisions by increasing the value of limit (and taking the
according dimension adjustments into account). however, if this yields
no improvement it is advised to analyze the integrand in order to
determine the integration difficulties. if the position of a local
difficulty can be determined (i.e. singularity discontinuity within
the interval), it should be supplied to the routine as an element of
the vector points. If necessary an appropriate special-purpose integrator
must be used, which is designed for handling the type of difficulty involved.
'''
_ERRORMESSAGE[2] ='''
the occurrence of roundoff error is detected, which prevents the requested
tolerance from being achieved. The error may be under-estimated.'''
_ERRORMESSAGE[3] ='''
Extremely bad integrand behaviour occurs at some points of the integration interval.'''
_ERRORMESSAGE[4] ='''
The algorithm does not converge. Roundoff error is detected in the extrapolation table.
It is presumed that the requested tolerance cannot be achieved, and that
the returned result is the best which can be obtained.'''
_ERRORMESSAGE[5] ='''
The integral is probably divergent, or slowly convergent.
It must be noted that divergence can occur with any other value of ier>0.'''
_ERRORMESSAGE[6] ='''the input is invalid because:
1) npts2 < 2
2) break points are specified outside the integration range
3) (epsabs<=0 and epsrel<max(50*rel.mach.acc.,0.5d-28))
4) limit < npts2.'''
def prbnormnd(correl,a,b,abseps=1e-4,releps=1e-3,maxpts=None,method=0):
'''
Multivariate Normal probability by Genz' algorithm.
Parameters
CORREL = Positive semidefinite correlation matrix
A = vector of lower integration limits.
B = vector of upper integration limits.
ABSEPS = absolute error tolerance.
RELEPS = relative error tolerance.
MAXPTS = maximum number of function values allowed. This
parameter can be used to limit the time. A sensible
strategy is to start with MAXPTS = 1000*N, and then
increase MAXPTS if ERROR is too large.
METHOD = integer defining the integration method
-1 KRBVRC randomized Korobov rules for the first 20
variables, randomized Richtmeyer rules for the rest,
NMAX = 500
0 KRBVRC, NMAX = 100 (default)
1 SADAPT Subregion Adaptive integration method, NMAX = 20
2 KROBOV Randomized KOROBOV rules, NMAX = 100
3 RCRUDE Crude Monte-Carlo Algorithm with simple
antithetic variates and weighted results on restart
4 SPHMVN Monte-Carlo algorithm by Deak (1980), NMAX = 100
Returns
-------
VALUE REAL estimated value for the integral
ERROR REAL estimated absolute error, with 99% confidence level.
INFORM INTEGER, termination status parameter:
if INFORM = 0, normal completion with ERROR < EPS;
if INFORM = 1, completion with ERROR > EPS and MAXPTS
function vaules used; increase MAXPTS to
decrease ERROR;
if INFORM = 2, N > NMAX or N < 1. where NMAX depends on the
integration method
Example:% Compute the probability that X1<0,X2<0,X3<0,X4<0,X5<0,
% Xi are zero-mean Gaussian variables with variances one
% and correlations Cov(X(i),X(j))=0.3:
% indI=[0 5], and barriers B_lo=[-inf 0], B_lo=[0 inf]
% gives H_lo = [-inf -inf -inf -inf -inf] H_lo = [0 0 0 0 0]
N = 5; rho=0.3; NIT=3; Nt=N; indI=[0 N];
B_lo=-10; B_up=0; m=1.2*ones(N,1);
Sc=(ones(N)-eye(N))*rho+eye(N);
E = rind(Sc,m,B_lo,B_up,indI,[],Nt) % exact prob. 0.00195
A = [-inf -inf -inf -inf -inf],
B = [0 0 0 0 0]-m'
[val,err,inform] = prbnormnd(Sc,A,B);
See also
--------
prbnormndpc, rind
'''
m,n = correl.shape
Na = len(a)
Nb = len(b)
if (m!=n or m!=Na or m!=Nb):
raise ValueError('Size of input is inconsistent!')
if maxpts is None:
maxpts = 1000*n
maxpts = max(round(maxpts),10*n);
# % array of correlation coefficients; the correlation
# % coefficient in row I column J of the correlation matrix
# % should be stored in CORREL( J + ((I-2)*(I-1))/2 ), for J < I.
# % The correlation matrix must be positive semidefinite.
D = np.diag(correl)
if (any(D!=1)):
raise ValueError('This is not a correlation matrix')
# Make sure integration limits are finite
A = np.clip(a,-100,100)
B = np.clip(b,-100, 100)
#L = correl((triu(ones(m),1)~=0)); % return only off diagonal elements
return mvn.mvnun(A,B, correl,maxpts, abseps, releps)
#CALL the mexroutine
# t0 = clock;
# if ((method==0) && (n<=100)),
# %NMAX = 100
# [value, err,inform] = mexmvnprb(L,A,B,abseps,releps,maxpts);
# elseif ( (method<0) || ((method<=0) && (n>100)) ),
# % NMAX = 500
# [value, err,inform] = mexmvnprb2(L,A,B,abseps,releps,maxpts);
# else
# [value, err,inform] = mexGenzMvnPrb(L,A,B,abseps,releps,maxpts,method);
# end
# exTime = etime(clock,t0);
#
if __name__ == '__main__':
if False: #True: #

@ -6,45 +6,11 @@ from __future__ import division
import sys
import numpy as np
from numpy import abs
from numpy import amax
from numpy import any
from numpy import arange
from numpy import arctan2
from numpy import array
from numpy import asarray
from numpy import atleast_1d
from numpy import broadcast_arrays
from numpy import ceil
from numpy import cos
from numpy import diff
from numpy import empty_like
from numpy import exp
from numpy import extract
from numpy import finfo
from numpy import floor
from numpy import frexp
from numpy import hstack
from numpy import hypot
from numpy import inf
from numpy import interp
from numpy import isnan
from numpy import isscalar
from numpy import linspace
from numpy import log
from numpy import logical_and
from numpy import mod
from numpy import nonzero
from numpy import ones
from numpy import pi
from numpy import r_
from numpy import sign
from numpy import sin
from numpy import sqrt
from numpy import unique
from numpy import vstack
from numpy import where
from numpy import zeros
from numpy import (abs, amax, any, logical_and, arange, linspace, atleast_1d,
array, asarray, broadcast_arrays, ceil, floor, frexp, hypot,
sqrt, arctan2, sin, cos, exp, log, mod, diff, empty_like,
finfo, inf, pi, interp, isnan, isscalar, zeros, ones,
r_, sign, unique, hstack, vstack, nonzero, where, extract)
from scipy.special import gammaln
import types
import warnings
@ -99,7 +65,12 @@ class DotDict(dict):
class Bunch(object):
''' Implement keyword argument initialization of class
Example
-------
>>> d = Bunch(test1=1,test2=3)
>>> d.test1
1
'''
def __init__(self, **kwargs):
self.__dict__.update(kwargs)
@ -1293,7 +1264,7 @@ def betaloge(z, w):
for large arguments
Example
>>> betaloge(3,2)
See also
@ -1496,7 +1467,7 @@ def discretize2(fun, a,b,tol=0.005, n=5):
return x, fx
def pol2cart(theta, rho):
def pol2cart(theta, rho, z=None):
'''
Transform polar coordinates into 2D cartesian coordinates.
@ -1509,9 +1480,14 @@ def pol2cart(theta, rho):
--------
cart2pol
'''
return rho * cos(theta), rho * sin(theta)
x, y = rho * cos(theta), rho * sin(theta)
if z is None:
return x, y
else:
return x,y,z
def cart2pol(x, y):
def cart2pol(x, y, z=None):
''' Transform 2D cartesian coordinates into polar coordinates.
Returns
@ -1525,7 +1501,12 @@ def cart2pol(x, y):
--------
pol2cart
'''
return arctan2(y, x), hypot(x, y)
t, r = arctan2(y, x), hypot(x, y)
if z is None:
return t,r
else:
return t, r, z
def meshgrid(*xi, ** kwargs):
"""
@ -1865,10 +1846,10 @@ def tranproc(x, f, x0, *xi):
return y #y0,y1,y2,y3,y4
def test_find_cross():
def _test_find_cross():
t = findcross([0, 0, 1, -1, 1],0)
def test_common_shape():
def _test_common_shape():
A = ones((4, 1))
B = 2
@ -1883,7 +1864,7 @@ def test_common_shape():
common_shape(A, B, C, shape=(4, 5))
def test_meshgrid():
def _test_meshgrid():
x = array([-1, -0.5, 1, 4, 5], float)
y = array([0, -2, -5], float)
xv, yv = meshgrid(x, y, sparse=False)

@ -206,7 +206,7 @@ def reslife(data, u=None, umin=None, umax=None, nu=None, nmin=3, alpha=0.05, plo
res = WafoData(mrl, u, xlab='Threshold', ylab='Mean Excess', title=titleTxt)
res.workspace = dict(numdata=num, umin=umin, umax=umax, nu=nu, nmin=nmin, alpha=alpha)
res.children = [WafoData(vstack([mrll, mrlu]).T, u, xlab='Threshold', title=titleTxt)]
res.children_args = [':r']
res.plot_args_children = [':r']
if plotflag:
res.plot()
return res
@ -371,7 +371,7 @@ def dispersion_idx(data, t=None, u=None, umin=None, umax=None, nu=None, nmin=10,
#'caption',CItxt);
res.workspace = dict(umin=umin, umax=umax, nu=nu, nmin=nmin, alpha=alpha)
res.children = [WafoData(vstack([diLo * ones(nu), diUp * ones(nu)]).T, u, xlab='Threshold', title=CItxt)]
res.children_args = ['--r']
res.plot_args_children = ['--r']
if plotflag:
res.plot(di)
return res, b_u, ok_u

@ -36,6 +36,7 @@ all = alltrue
def chi2isf(p, df):
return special.chdtri(df, p)
def chi2sf(x, df):
return special.chdtrc(df, x)

@ -0,0 +1,111 @@
'''
Created on 17. juli 2010
@author: pab
'''
import numpy as np
from numpy import pi, inf
from wafo.gaussian import Rind, prbnormtndpc, prbnormndpc
def test_rind():
'''
>>> Et = 0.001946 # # exact prob.
>>> n = 5
>>> Blo =-np.inf; Bup=-1.2; indI=[-1, n-1] # Barriers
>>> m = np.zeros(n); rho = 0.3;
>>> Sc =(np.ones((n,n))-np.eye(n))*rho+np.eye(n)
>>> rind = Rind()
>>> E0, err0, terr0 = rind(Sc,m,Blo,Bup,indI);
>>> np.abs(E0-Et)< err0+terr0
array([ True], dtype=bool)
>>> 'E0 = %2.6f' % E0
'E0 = 0.001946'
>>> A = np.repeat(Blo,n); B = np.repeat(Bup,n) # Integration limits
>>> E1, err1, terr1 = rind(np.triu(Sc),m,A,B); #same as E0
>>> np.abs(E1-Et)< err0+terr0
array([ True], dtype=bool)
>>> 'E1 = %2.6f' % E1
'E1 = 0.001946'
Compute expectation E( abs(X1*X2*...*X5) )
>>> xc = np.zeros((0,1))
>>> infinity = 37
>>> dev = np.sqrt(np.diag(Sc)) # std
>>> ind = np.nonzero(indI[1:])[0]
>>> Bup, Blo = np.atleast_2d(Bup,Blo)
>>> Bup[0,ind] = np.minimum(Bup[0,ind] , infinity*dev[indI[ind+1]])
>>> Blo[0,ind] = np.maximum(Blo[0,ind] ,-infinity*dev[indI[ind+1]])
>>> rind(Sc,m,Blo,Bup,indI, xc, nt=0)
(array([ 0.05494076]), array([ 0.00083066]), array([ 1.00000000e-10]))
Compute expectation E( X1^{+}*X2^{+} ) with random
correlation coefficient,Cov(X1,X2) = rho2.
>>> m2 = [0, 0];
>>> rho2 = 0.3 #np.random.rand(1)
>>> Sc2 = [[1, rho2], [rho2 ,1]]
>>> Blo2 = 0; Bup2 = np.inf; indI2 = [-1, 1]
>>> rind2 = Rind(method=1)
>>> g2 = lambda x : (x*(np.pi/2+np.arcsin(x))+np.sqrt(1-x**2))/(2*np.pi)
>>> E2 = g2(rho2); E2 # exact value
0.24137214191774381
>>> E3, err3, terr3 = rind(Sc2,m2,Blo2,Bup2,indI2,nt=0); E3;err3;terr3
array([ 0.24127499])
array([ 0.00013838])
array([ 1.00000000e-10])
>>> E4, err4, terr4 = rind2(Sc2,m2,Blo2,Bup2,indI2,nt=0); E4;err4;terr4
array([ 0.24127499])
array([ 0.00013838])
array([ 1.00000000e-10])
>>> E5, err5, terr5 = rind2(Sc2,m2,Blo2,Bup2,indI2,nt=0,abseps=1e-4); E5;err5;terr5
array([ 0.24127499])
array([ 0.00013838])
array([ 1.00000000e-10])
'''
def test_prbnormtndpc():
'''
>>> rho2 = np.random.rand(2);
>>> a2 = np.zeros(2);
>>> b2 = np.repeat(np.inf,2);
>>> [val2,err2, ift2] = prbnormtndpc(rho2,a2,b2)
>>> g2 = lambda x : 0.25+np.arcsin(x[0]*x[1])/(2*pi)
>>> E2 = g2(rho2) #% exact value
>>> np.abs(E2-val2)<err2
True
>>> rho3 = np.random.rand(3)
>>> a3 = np.zeros(3)
>>> b3 = np.repeat(inf,3)
>>> [val3,err3, ift3] = prbnormtndpc(rho3,a3,b3)
>>> g3 = lambda x : 0.5-sum(np.sort(np.arccos([x[0]*x[1],x[0]*x[2],x[1]*x[2]])))/(4*pi)
>>> E3 = g3(rho3) # Exact value
>>> np.abs(E3-val3)<err2
True
'''
def test_prbnormndpc():
'''
>>> rho2 = np.random.rand(2);
>>> a2 = np.zeros(2);
>>> b2 = np.repeat(np.inf,2);
>>> [val2,err2, ift2] = prbnormndpc(rho2,a2,b2)
>>> g2 = lambda x : 0.25+np.arcsin(x[0]*x[1])/(2*pi)
>>> E2 = g2(rho2) #% exact value
>>> np.abs(E2-val2)<err2
True
>>> rho3 = np.random.rand(3)
>>> a3 = np.zeros(3)
>>> b3 = np.repeat(inf,3)
>>> [val3,err3, ift3] = prbnormndpc(rho3,a3,b3)
>>> g3 = lambda x : 0.5-sum(np.sort(np.arccos([x[0]*x[1],x[0]*x[2],x[1]*x[2]])))/(4*pi)
>>> E3 = g3(rho3) # Exact value
>>> np.abs(E3-val3)<err2
True
'''
if __name__ == '__main__':
import doctest
doctest.testmod()

@ -1,14 +1,33 @@
from pylab import cos, randn, exp, linspace, pi, sin
from wafo.misc import detrendma, DotDict, findcross, ecross
import numpy as np
from numpy import cos, exp, linspace, pi, sin, diff, arange, ones
from numpy.random import randn
from wafo.data import sea
from wafo.misc import (JITImport, Bunch, detrendma, DotDict, findcross, ecross, findextrema,
findrfc, rfcfilter, findtp, findtc, findoutliers,
common_shape, argsreduce, stirlerr, getshipchar, betaloge,
gravity, nextpow2, discretize, discretize2, pol2cart,
cart2pol, meshgrid, tranproc)
def test_JITImport():
'''
>>> np = JITImport('numpy')
>>> np.exp(0)==1.0
True
'''
def test_bunch():
'''
>>> d = Bunch(test1=1,test2=3)
>>> d.test1; d.test2
1
3
'''
def test_dotdict():
'''
>>> d = DotDict(test1=1,test2=3)
>>> d.test1
>>> d.test1; d.test2
1
3
'''
pass
def test_detrendma():
'''
@ -123,9 +142,14 @@ def test_detrendma():
2.44120808, 2.44120808, 2.44120808, 2.44120808, 2.44120808,
2.44120808, 2.44120808, 2.44120808, 2.44120808, 2.44120808]))
'''
pass
def test_findcross_and_ecross():
'''
>>> findcross([0, 0, 1, -1, 1],0)
array([1, 2, 3])
>>> findcross([0, 1, -1, 1],0)
array([0, 1, 2])
>>> t = linspace(0,7*pi,250)
>>> x = sin(t)
>>> ind = findcross(x,0.75)
@ -136,6 +160,321 @@ def test_findcross_and_ecross():
array([ 0.84910514, 2.2933879 , 7.13205663, 8.57630119,
13.41484739, 14.85909194, 19.69776067, 21.14204343])
'''
def test_findextrema():
'''
>>> t = linspace(0,7*pi,250)
>>> x = sin(t)
>>> ind = findextrema(x)
>>> ind
array([ 18, 53, 89, 125, 160, 196, 231])
'''
def test_findrfc():
'''
>>> t = linspace(0,7*pi,250)
>>> x = sin(t)+0.1*sin(50*t)
>>> ind = findextrema(x)
>>> ind
array([ 1, 3, 4, 6, 7, 9, 11, 13, 14, 16, 18, 19, 21,
23, 25, 26, 28, 29, 31, 33, 35, 36, 38, 39, 41, 43,
45, 46, 48, 50, 51, 53, 55, 56, 58, 60, 61, 63, 65,
67, 68, 70, 71, 73, 75, 77, 78, 80, 81, 83, 85, 87,
88, 90, 92, 93, 95, 97, 99, 100, 102, 103, 105, 107, 109,
110, 112, 113, 115, 117, 119, 120, 122, 124, 125, 127, 129, 131,
132, 134, 135, 137, 139, 141, 142, 144, 145, 147, 149, 151, 152,
154, 156, 157, 159, 161, 162, 164, 166, 167, 169, 171, 173, 174,
176, 177, 179, 181, 183, 184, 186, 187, 189, 191, 193, 194, 196,
198, 199, 201, 203, 205, 206, 208, 209, 211, 213, 215, 216, 218,
219, 221, 223, 225, 226, 228, 230, 231, 233, 235, 237, 238, 240,
241, 243, 245, 247, 248])
>>> ti, tp = t[ind], x[ind]
>>> ind1 = findrfc(tp,0.3)
>>> ind1
array([ 0, 9, 32, 53, 74, 95, 116, 137])
>>> tp[ind1]
array([-0.00743352, 1.08753972, -1.07206545, 1.09550837, -1.07940458,
1.07849396, -1.0995006 , 1.08094452])
'''
def test_rfcfilter():
'''
# 1. Filtered signal y is the turning points of x.
>>> x = sea()
>>> y = rfcfilter(x[:,1], h=0, method=1)
>>> y[0:5]
array([-1.2004945 , 0.83950546, -0.09049454, -0.02049454, -0.09049454])
# 2. This removes all rainflow cycles with range less than 0.5.
>>> y1 = rfcfilter(x[:,1], h=0.5)
>>> y1[0:5]
array([-1.2004945 , 0.83950546, -0.43049454, 0.34950546, -0.51049454])
>>> t = linspace(0,7*pi,250)
>>> x = sin(t)+0.1*sin(50*t)
>>> ind = findextrema(x)
>>> ind
array([ 1, 3, 4, 6, 7, 9, 11, 13, 14, 16, 18, 19, 21,
23, 25, 26, 28, 29, 31, 33, 35, 36, 38, 39, 41, 43,
45, 46, 48, 50, 51, 53, 55, 56, 58, 60, 61, 63, 65,
67, 68, 70, 71, 73, 75, 77, 78, 80, 81, 83, 85, 87,
88, 90, 92, 93, 95, 97, 99, 100, 102, 103, 105, 107, 109,
110, 112, 113, 115, 117, 119, 120, 122, 124, 125, 127, 129, 131,
132, 134, 135, 137, 139, 141, 142, 144, 145, 147, 149, 151, 152,
154, 156, 157, 159, 161, 162, 164, 166, 167, 169, 171, 173, 174,
176, 177, 179, 181, 183, 184, 186, 187, 189, 191, 193, 194, 196,
198, 199, 201, 203, 205, 206, 208, 209, 211, 213, 215, 216, 218,
219, 221, 223, 225, 226, 228, 230, 231, 233, 235, 237, 238, 240,
241, 243, 245, 247, 248])
>>> ti, tp = t[ind], x[ind]
>>> tp03 = rfcfilter(tp,0.3)
>>> tp03
array([-0.00743352, 1.08753972, -1.07206545, 1.09550837, -1.07940458,
1.07849396, -1.0995006 , 1.08094452])
'''
def test_findtp():
'''
>>> x = sea()
>>> x1 = x[0:200,:]
>>> itp = findtp(x1[:,1],0,'Mw')
>>> itph = findtp(x1[:,1],0.3,'Mw')
>>> itp
array([ 11, 21, 22, 24, 26, 28, 31, 39, 43, 45, 47, 51, 56,
64, 70, 78, 82, 84, 89, 94, 101, 108, 119, 131, 141, 148,
149, 150, 159, 173, 184, 190, 199])
>>> itph
array([ 11, 64, 28, 31, 47, 51, 39, 56, 70, 94, 78, 89, 101,
108, 119, 148, 131, 141, 0, 159, 173, 184, 190])
'''
def test_findtc():
'''
>>> x = sea()
>>> x1 = x[0:200,:]
>>> itc, iv = findtc(x1[:,1],0,'dw')
>>> itc
array([ 28, 31, 39, 56, 64, 69, 78, 82, 83, 89, 94, 101, 108,
119, 131, 140, 148, 159, 173, 184])
>>> iv
array([ 19, 29, 34, 53, 60, 67, 76, 81, 82, 84, 90, 99, 103,
112, 127, 137, 143, 154, 166, 180, 185])
'''
def test_findoutliers():
'''
>>> xx = sea()
>>> dt = diff(xx[:2,0])
>>> dcrit = 5*dt
>>> ddcrit = 9.81/2*dt*dt
>>> zcrit = 0
>>> [inds, indg] = findoutliers(xx[:,1],zcrit,dcrit,ddcrit,verbose=True)
Found 0 spurious positive jumps of Dx
Found 0 spurious negative jumps of Dx
Found 37 spurious positive jumps of D^2x
Found 200 spurious negative jumps of D^2x
Found 244 consecutive equal values
Found the total of 1152 spurious points
>>> inds
array([ 6, 7, 8, ..., 9509, 9510, 9511])
>>> indg
array([ 0, 1, 2, ..., 9521, 9522, 9523])
'''
def test_common_shape():
'''
>>> import numpy as np
>>> A = np.ones((4,1))
>>> B = 2
>>> C = np.ones((1,5))*5
>>> common_shape(A,B,C)
(4, 5)
>>> common_shape(A,B,C,shape=(3,4,1))
(3, 4, 5)
>>> A = np.ones((4,1))
>>> B = 2
>>> C = np.ones((1,5))*5
>>> common_shape(A,B,C)
(4, 5)
>>> common_shape(A,B,C,shape=(3,4,1))
(3, 4, 5)
'''
def test_argsreduce():
'''
>>> import numpy as np
>>> rand = np.random.random_sample
>>> A = linspace(0,19,20).reshape((4,5))
>>> B = 2
>>> C = range(5)
>>> cond = np.ones(A.shape)
>>> [A1,B1,C1] = argsreduce(cond,A,B,C)
>>> B1.shape
(20,)
>>> cond[2,:] = 0
>>> [A2,B2,C2] = argsreduce(cond,A,B,C)
>>> B2.shape
(15,)
>>> A2;B2;C2
array([ 0., 1., 2., 3., 4., 5., 6., 7., 8., 9., 15.,
16., 17., 18., 19.])
array([2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2])
array([0, 1, 2, 3, 4, 0, 1, 2, 3, 4, 0, 1, 2, 3, 4])
'''
def test_stirlerr():
'''
>>> stirlerr(range(5))
array([ Inf, 0.08106147, 0.0413407 , 0.02767793, 0.02079067])
'''
def test_getshipchar():
'''
>>> sc = getshipchar(10,'service_speed')
>>> names = ['beam', 'beamSTD', 'draught',
... 'draughtSTD', 'length', 'lengthSTD',
... 'max_deadweight', 'max_deadweightSTD', 'propeller_diameter',
... 'propeller_diameterSTD', 'service_speed', 'service_speedSTD']
>>> for name in names: print( '%s : %g' % (name, sc[name]))
beam : 29
beamSTD : 2.9
draught : 9.6
draughtSTD : 2.112
length : 216
lengthSTD : 2.01131
max_deadweight : 30969
max_deadweightSTD : 3096.9
propeller_diameter : 6.76117
propeller_diameterSTD : 0.20267
service_speed : 10
service_speedSTD : 0
'''
def test_betaloge():
'''
>>> betaloge(3, arange(4))
array([ Inf, -1.09861229, -2.48490665, -3.40119738])
'''
def test_gravity():
'''
>>> phi = linspace(0,45,5)
>>> gravity(phi)
array([ 9.78049 , 9.78245014, 9.78803583, 9.79640552, 9.80629387])
'''
def test_nextpow2():
'''
>>> nextpow2(10)
4
>>> nextpow2(np.arange(5))
3
'''
def test_discretize():
'''
>>> x, y = discretize(np.cos,0,np.pi)
>>> x; y
array([ 0. , 0.19634954, 0.39269908, 0.58904862, 0.78539816,
0.9817477 , 1.17809725, 1.37444679, 1.57079633, 1.76714587,
1.96349541, 2.15984495, 2.35619449, 2.55254403, 2.74889357,
2.94524311, 3.14159265])
array([ 1.00000000e+00, 9.80785280e-01, 9.23879533e-01,
8.31469612e-01, 7.07106781e-01, 5.55570233e-01,
3.82683432e-01, 1.95090322e-01, 6.12323400e-17,
-1.95090322e-01, -3.82683432e-01, -5.55570233e-01,
-7.07106781e-01, -8.31469612e-01, -9.23879533e-01,
-9.80785280e-01, -1.00000000e+00])
'''
def test_discretize2():
'''
>>> x, y = discretize2(np.cos,0,np.pi)
>>> x; y
array([ 0. , 0.19634954, 0.39269908, 0.58904862, 0.78539816,
0.9817477 , 1.17809725, 1.37444679, 1.57079633, 1.76714587,
1.96349541, 2.15984495, 2.35619449, 2.55254403, 2.74889357,
2.94524311, 3.14159265])
array([ 1.00000000e+00, 9.80785280e-01, 9.23879533e-01,
8.31469612e-01, 7.07106781e-01, 5.55570233e-01,
3.82683432e-01, 1.95090322e-01, 6.12323400e-17,
-1.95090322e-01, -3.82683432e-01, -5.55570233e-01,
-7.07106781e-01, -8.31469612e-01, -9.23879533e-01,
-9.80785280e-01, -1.00000000e+00])
'''
def test_pol2cart_n_cart2pol():
'''
>>> r = 5
>>> t = linspace(0,pi,20)
>>> x, y = pol2cart(t,r)
>>> x; y
array([ 5. , 4.93180652, 4.72908621, 4.39736876, 3.94570255,
3.38640786, 2.73474079, 2.00847712, 1.22742744, 0.41289673,
-0.41289673, -1.22742744, -2.00847712, -2.73474079, -3.38640786,
-3.94570255, -4.39736876, -4.72908621, -4.93180652, -5. ])
array([ 0.00000000e+00, 8.22972951e-01, 1.62349735e+00,
2.37973697e+00, 3.07106356e+00, 3.67861955e+00,
4.18583239e+00, 4.57886663e+00, 4.84700133e+00,
4.98292247e+00, 4.98292247e+00, 4.84700133e+00,
4.57886663e+00, 4.18583239e+00, 3.67861955e+00,
3.07106356e+00, 2.37973697e+00, 1.62349735e+00,
8.22972951e-01, 6.12323400e-16])
>>> ti, ri = cart2pol(x,y)
>>> ti;ri
array([ 0. , 0.16534698, 0.33069396, 0.49604095, 0.66138793,
0.82673491, 0.99208189, 1.15742887, 1.32277585, 1.48812284,
1.65346982, 1.8188168 , 1.98416378, 2.14951076, 2.31485774,
2.48020473, 2.64555171, 2.81089869, 2.97624567, 3.14159265])
array([ 5., 5., 5., 5., 5., 5., 5., 5., 5., 5., 5., 5., 5.,
5., 5., 5., 5., 5., 5., 5.])
'''
def test_meshgrid():
'''
>>> x = np.linspace(0,1,3) # coordinates along x axis
>>> y = np.linspace(0,1,2) # coordinates along y axis
>>> xv, yv = meshgrid(x,y) # extend x and y for a 2D xy grid
>>> xv
array([[ 0. , 0.5, 1. ],
[ 0. , 0.5, 1. ]])
>>> yv
array([[ 0., 0., 0.],
[ 1., 1., 1.]])
>>> xv, yv = meshgrid(x,y, sparse=True) # make sparse output arrays
>>> xv
array([[ 0. , 0.5, 1. ]])
>>> yv
array([[ 0.],
[ 1.]])
>>> meshgrid(x,y,sparse=True,indexing='ij') # change to matrix indexing
[array([[ 0. ],
[ 0.5],
[ 1. ]]), array([[ 0., 1.]])]
>>> meshgrid(x,y,indexing='ij')
[array([[ 0. , 0. ],
[ 0.5, 0.5],
[ 1. , 1. ]]), array([[ 0., 1.],
[ 0., 1.],
[ 0., 1.]])]
>>> meshgrid(0,1,5) # just a 3D point
[array([[[0]]]), array([[[1]]]), array([[[5]]])]
>>> map(np.squeeze,meshgrid(0,1,5)) # just a 3D point
[array(0), array(1), array(5)]
>>> meshgrid(3)
array([3])
>>> meshgrid(y) # 1D grid y is just returned
array([ 0., 1.])
`meshgrid` is very useful to evaluate functions on a grid.
>>> x = np.arange(-5, 5, 0.1)
>>> y = np.arange(-5, 5, 0.1)
>>> xx, yy = meshgrid(x, y, sparse=True)
>>> z = np.sin(xx**2+yy**2)/(xx**2+yy**2)
'''
def test_tranproc():
'''
>>> import wafo.transform.models as wtm
>>> tr = wtm.TrHermite()
>>> x = linspace(-5,5,501)
>>> g = tr(x)
>>> y0, y1 = tranproc(x, g, range(5), ones(5))
>>> y0;y1
array([ 0.02659612, 1.00115284, 1.92872532, 2.81453257, 3.66292878])
array([ 1.00005295, 0.9501118 , 0.90589954, 0.86643821, 0.83096482])
'''
if __name__=='__main__':
import doctest

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