我似乎无法让 control.ss2tf() 函数用于状态空间 MIMO 系统。该功能非常适用于 SISO 系统。
以下代码用于运行该模块：
control.ss2tf(A,B,C,D)
结果输出表明未安装 slycot 模块。
然后我尝试安装 slycot
pip install slycot
该命令给出以下输出：
Failed building wheel for slycot
Running setup.py clean for slycot
Failed to build slycot
Installing collected packages: slycot
Running setup.py install for slycot ... error
Complete output from command c:\users\wian\anaconda3\python.exe -u -c "import setuptools, tokenize;__file__='C:\\Users\\Wian\\AppData\\Local\\Temp\\pip-install-cmcxwtts\\slycot\\setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record C:\Users\Wian\AppData\Local\Temp\pip-record-_n6gj2yv\install-record.txt --single-version-externally-managed --compile:
Running from numpy source directory.
running install
running build
running config_cc
unifing config_cc, config, build_clib, build_ext, build commands --compiler options
running config_fc
unifing config_fc, config, build_clib, build_ext, build commands --fcompiler options
running build_src
build_src
building py_modules sources
building extension "slycot._wrapper" sources
f2py options: []
adding 'build\src.win-amd64-3.6\build\src.win-amd64-3.6\slycot\src\fortranobject.c' to sources.
adding 'build\src.win-amd64-3.6\build\src.win-amd64-3.6\slycot\src' to include_dirs.
adding 'build\src.win-amd64-3.6\slycot\src\_wrapper-f2pywrappers.f' to sources.
build_src: building npy-pkg config files
running build_py
copying slycot\version.py -> build\lib.win-amd64-3.6\slycot
copying build\src.win-amd64-3.6\slycot\__config__.py -> build\lib.win-amd64-3.6\slycot
running build_ext
Looking for python36.dll
Building import library (arch=AMD64): "c:\users\wian\anaconda3\libs\libpython36.a" (from c:\users\wian\anaconda3\python36.dll)
objdump.exe: c:\users\wian\anaconda3\python36.dll: file format not recognized
Traceback (most recent call last):
File "<string>", line 1, in <module>
File "C:\Users\Wian\AppData\Local\Temp\pip-install-cmcxwtts\slycot\setup.py", line 241, in <module>
setup_package()
File "C:\Users\Wian\AppData\Local\Temp\pip-install-cmcxwtts\slycot\setup.py", line 233, in setup_package
setup(**metadata)
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\core.py", line 171, in setup
return old_setup(**new_attr)
File "c:\users\wian\anaconda3\lib\site-packages\setuptools\__init__.py", line 145, in setup
return distutils.core.setup(**attrs)
File "c:\users\wian\anaconda3\lib\distutils\core.py", line 148, in setup
dist.run_commands()
File "c:\users\wian\anaconda3\lib\distutils\dist.py", line 955, in run_commands
self.run_command(cmd)
File "c:\users\wian\anaconda3\lib\distutils\dist.py", line 974, in run_command
cmd_obj.run()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\command\install.py", line 62, in run
r = self.setuptools_run()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\command\install.py", line 36, in setuptools_run
return distutils_install.run(self)
File "c:\users\wian\anaconda3\lib\distutils\command\install.py", line 545, in run
self.run_command('build')
File "c:\users\wian\anaconda3\lib\distutils\cmd.py", line 313, in run_command
self.distribution.run_command(command)
File "c:\users\wian\anaconda3\lib\distutils\dist.py", line 974, in run_command
cmd_obj.run()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\command\build.py", line 47, in run
old_build.run(self)
File "c:\users\wian\anaconda3\lib\distutils\command\build.py", line 135, in run
self.run_command(cmd_name)
File "c:\users\wian\anaconda3\lib\distutils\cmd.py", line 313, in run_command
self.distribution.run_command(command)
File "c:\users\wian\anaconda3\lib\distutils\dist.py", line 974, in run_command
cmd_obj.run()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\command\build_ext.py", line 116, in run
force=self.force)
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\ccompiler.py", line 765, in new_compiler
compiler = klass(None, dry_run, force)
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\mingw32ccompiler.py", line 103, in __init__
build_import_library()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\mingw32ccompiler.py", line 415, in build_import_library
return _build_import_library_amd64()
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\mingw32ccompiler.py", line 471, in _build_import_library_amd64
generate_def(dll_file, def_file)
File "c:\users\wian\anaconda3\lib\site-packages\numpy\distutils\mingw32ccompiler.py", line 301, in generate_def
raise ValueError("Symbol table not found")
ValueError: Symbol table not found
我读到这是由于系统上未安装 FORTRAN 编译器。因此我用 Ming32 安装了 gfortran。为了验证安装，我运行了以下命令：
(base) C:\WINDOWS\system32>gfortran
gfortran: fatal error: no input files
compilation terminated.
所以 gfortran 作为编译器安装，但 pip 仍然无法安装 slycot。我还安装了 Microsoft Visual Studio 2017。
此时我去 PyPi 库下载了 slycot 模块的编译后的二进制文件。https://www.lfd.uci.edu/~gohlke/pythonlibs/
在这里，我为我的系统（64 位 Python 3.6）下载了正确的 .whl 文件，并使用 pip 安装了它。
pip install "C:\Users\Wian\Desktop\slycot-0.3.3-cp36-cp36m-win_amd64.whl"
使用此命令成功安装了 slycot 0.3.3。但是，当我运行命令时
control.ss2tf(A,B,C,D)
我得到以下输出
---------------------------------------------------------------------------
ImportError Traceback (most recent call last)
~\Anaconda3\lib\site-packages\control\xferfcn.py in _convertToTransferFunction(sys, **kw)
1089 try:
-> 1090 from slycot import tb04ad
1091 if len(kw):
ImportError: cannot import name 'tb04ad'
During handling of the above exception, another exception occurred:
TypeError Traceback (most recent call last)
<ipython-input-8-2b014ac15956> in <module>()
----> 1 control.ss2tf(Model)
~\Anaconda3\lib\site-packages\control\xferfcn.py in ss2tf(*args)
1315 sys = args[0]
1316 if isinstance(sys, StateSpace):
-> 1317 return _convertToTransferFunction(sys)
1318 else:
1319 raise TypeError("ss2tf(sys): sys must be a StateSpace object. It \
~\Anaconda3\lib\site-packages\control\xferfcn.py in _convertToTransferFunction(sys, **kw)
1113 # If slycot is not available, use signal.lti (SISO only)
1114 if (sys.inputs != 1 or sys.outputs != 1):
-> 1115 raise TypeError("No support for MIMO without slycot")
1116
1117 # Do the conversion using sp.signal.ss2tf
TypeError: No support for MIMO without slycot
当我尝试在 Python 中导入 slycot 时，我得到以下结果：
>>> import slycot
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "C:\Users\Wian\Anaconda3\lib\site-packages\slycot\__init__.py", line 18, in <module>
from .analysis import ab01nd,ab05md,ab05nd,ab07nd,ab08nd, \
File "C:\Users\Wian\Anaconda3\lib\site-packages\slycot\analysis.py", line 21, in <module>
from . import _wrapper
ImportError: DLL load failed: The specified module could not be found.
在 Slycot 目录中有一个 _wrapper.pyd 文件（在 Anaconda3\Libs\site-packages 下）。
这是我目前陷入困境的地方，我无法让 Slycot 正确导入。
非常感谢您的帮助！