def chebyshev(trial, target, M=61):
from mystic.math import polyeval
result=0.0
x=-1.0
dx = 2.0 / (M-1)
for i in range(M):
px = polyeval(trial, x)
if px<-1 or px>1:
result += (1 - px) * (1 - px)
x += dx
px = polyeval(trial, 1.2) - polyeval(target, 1.2)
if px<0: result += px*px
px = polyeval(trial, -1.2) - polyeval(target, -1.2)
if px<0: result += px*px
return result
def chebyshev(trial, target, M=61):
from mystic.math import polyeval
result=0.0
x=-1.0
dx = 2.0 / (M-1)
for i in range(M):
px = polyeval(trial, x)
if px<-1 or px>1:
result += (1 - px) * (1 - px)
x += dx
px = polyeval(trial, 1.2) - polyeval(target, 1.2)
if px<0: result += px*px
px = polyeval(trial, -1.2) - polyeval(target, -1.2)
if px<0: result += px*px
return result
def chebyshevcost(trial,M=61):
"""The costfunction for order-n Chebyshev fitting.
M evaluation points between [-1, 1], and two end points"""
result=0.0
x=-1.0
dx = 2.0 / (M-1)
for i in range(M):
px = polyeval(trial, x)
if px<-1 or px>1:
result += (1 - px) * (1 - px)
x += dx
px = polyeval(trial, 1.2) - polyeval(target, 1.2)
if px<0: result += px*px
px = polyeval(trial, -1.2) - polyeval(target, -1.2)
if px<0: result += px*px
return result
def ChebyshevCost(trial,M=61):
"""The costfunction for order-n Chebyshev fitting.
M evaluation points between [-1, 1], and two end points"""
from mystic.models.poly import chebyshev8coeffs as target
from mystic.math import polyeval
result=0.0
x=-1.0
dx = 2.0 / (M-1)
for i in range(M):
px = polyeval(trial, x)
if px<-1 or px>1:
result += (1 - px) * (1 - px)
x += dx
px = polyeval(trial, 1.2) - polyeval(target, 1.2)
if px<0: result += px*px
px = polyeval(trial, -1.2) - polyeval(target, -1.2)
if px<0: result += px*px
return result
def ChebyshevCost(trial, M=61):
"""The costfunction for order-n Chebyshev fitting.
M evaluation points between [-1, 1], and two end points"""
from mystic.models.poly import chebyshev8coeffs as target
from mystic.math import polyeval
result = 0.0
x = -1.0
dx = 2.0 / (M - 1)
for i in range(M):
px = polyeval(trial, x)
if px < -1 or px > 1:
result += (1 - px) * (1 - px)
x += dx
px = polyeval(trial, 1.2) - polyeval(target, 1.2)
if px < 0: result += px * px
px = polyeval(trial, -1.2) - polyeval(target, -1.2)
if px < 0: result += px * px
return result
def objective(coeffs, x, y):
return polyeval(coeffs, x) - y
def objective(coeffs, x, y):
return polyeval(coeffs, x) - y
def evaluate(self, coeffs, x):
"""takes list of coefficients & evaluation points, returns f(x)
thus, [a3, a2, a1, a0] yields a3 x^3 + a2 x^2 + a1 x^1 + a0"""
return polyeval(coeffs, x)
def evaluate(self,coeffs,x):
"""takes list of coefficients & evaluation points, returns f(x)
thus, [a3, a2, a1, a0] yields a3 x^3 + a2 x^2 + a1 x^1 + a0"""
return polyeval(coeffs,x)