Question

我正在尝试使用scipy.odr将测量数据点拟合到我的模型中。虽然在没有指定jacobians的情况下进行拟合，但是对于某些模型会产生不良结果，但在使用某些模型指定我自己的jacobians时会出现分段错误。

#!/usr/bin/python2
from __future__ import print_function

import numpy as np
import scipy.odr as odr

tspace = np.linspace(0, 10, 100)

def fun(p, x):
    a, x0 = p
    r = a * (x - x0)**2
    return r

def param_jacobian(p, x, *args):
    a, x0 = p
    r = np.array([
        (x.T - x0)**2,
        -2*a*x0*(x.T - x0),
    ])
    return r

def value_jacobian(p, x, *args):
    a, x0 = p
    r = np.array([
        2*a*(x.T - x0),
    ])
    return r

correct = fun((0.5, 3), tspace)

p0 = (0.1, 1)

model = odr.Model(fun, fjacb=param_jacobian, fjacd=value_jacobian)
data = odr.Data(tspace, correct)

fitter = odr.ODR(data, model, beta0=p0)
fitter.set_job(0, 2)
fitter.run()
fitter.output.pprint()

此示例在python 2.7,64bit，scipy 0.9.0上发生了段错误。如果您通过调用fitter.set_job(0, 0)或fitter.set_job(0, 1)来切换自定义雅可比人的使用，则可以正常工作（此示例中的拟合结果很好，但其他人则没有。）

我的错误在哪里？这是我的错误吗？

更新：我再一次遇到了这个问题。我在fit脚本上运行了gdb和valgrind。 gdb将堆栈跟踪显示为malloc_consolidate，这被syslog模块的某些导入尝试深深调用...对我来说似乎很奇怪，但我认为这无关紧要，因为valgrind在{之后'显示以下两次第一次调用{1}}（在param_jacobian之后）。尝试获取结果时会发生段错误。我怀疑段错误是由于堆损坏造成的，这可能是value_jacobian中的错误。

odrpack.so

甚至在第二次调用==32764== Source and destination overlap in memcpy(0x14239ee0, 0x14239ee0, 32) ==32764== at 0x4A09306: memcpy@@GLIBC_2.14 (mc_replace_strmem.c:653) ==32764== by 0x1B3663EB: fcn_callback (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32764== by 0x1B3A1821: doddrv_ (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32764== by 0x1B3A282A: dodcnt_ (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32764== by 0x1B3A355A: dodrc_ (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32764== by 0x1B36A452: odr (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32764== by 0x3A41249382: PyObject_Call (abstract.c:2529) ==32764== by 0x3A412DA8F6: PyEval_CallObjectWithKeywords (ceval.c:3967) ==32764== by 0x3A412D89E9: builtin_apply (bltinmodule.c:195) ==32764== by 0x3A412E03DA: PyEval_EvalFrameEx (ceval.c:4098) ==32764== by 0x3A412E075D: PyEval_EvalFrameEx (ceval.c:4184) ==32764== by 0x3A412E19A4: PyEval_EvalCodeEx (ceval.c:3330)函数之后：

*_jacobian

和类似错误（同一函数中的==32100== Invalid read of size 8 ==32100== at 0x18189BFB: gen_output (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32100== by 0x1818C4BA: odr (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32100== by 0x3A41249382: PyObject_Call (abstract.c:2529) ==32100== by 0x3A412DA8F6: PyEval_CallObjectWithKeywords (ceval.c:3967) ==32100== by 0x3A412D89E9: builtin_apply (bltinmodule.c:195) ==32100== by 0x3A412E03DA: PyEval_EvalFrameEx (ceval.c:4098) ==32100== by 0x3A412E075D: PyEval_EvalFrameEx (ceval.c:4184) ==32100== by 0x3A412E19A4: PyEval_EvalCodeEx (ceval.c:3330) ==32100== by 0x3A412DFF02: PyEval_EvalFrameEx (ceval.c:4194) ==32100== by 0x3A412E19A4: PyEval_EvalCodeEx (ceval.c:3330) ==32100== by 0x3A412E1AD1: PyEval_EvalCode (ceval.c:689) ==32100== by 0x3A412FBD5B: run_mod (pythonrun.c:1361) ==32100== Address 0x10207b40 is 0 bytes inside a block of size 80 free'd ==32100== at 0x4A0662E: free (vg_replace_malloc.c:366) ==32100== by 0xC1050FF: ??? (in /usr/lib64/python2.7/site-packages/numpy/core/multiarray.so) ==32100== by 0xC110199: ??? (in /usr/lib64/python2.7/site-packages/numpy/core/multiarray.so) ==32100== by 0x18189A7E: gen_output (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32100== by 0x1818C4BA: odr (in /usr/lib64/python2.7/site-packages/scipy/odr/__odrpack.so) ==32100== by 0x3A41249382: PyObject_Call (abstract.c:2529) ==32100== by 0x3A412DA8F6: PyEval_CallObjectWithKeywords (ceval.c:3967) ==32100== by 0x3A412D89E9: builtin_apply (bltinmodule.c:195) ==32100== by 0x3A412E03DA: PyEval_EvalFrameEx (ceval.c:4098) ==32100== by 0x3A412E075D: PyEval_EvalFrameEx (ceval.c:4184) ==32100== by 0x3A412E19A4: PyEval_EvalCodeEx (ceval.c:3330) ==32100== by 0x3A412DFF02: PyEval_EvalFrameEx (ceval.c:4194)）多次。

我尝试Invalid read of size 8 this (mostly unrelated) bugreport发布的小型memcpy替换，但这没有帮助。

为什么这个scipy.odr适合使用自定义jacobians segfault？

0 个答案: