declared as array of references of type float&当我声明一个函数时,我在XCode中遇到错误:
void calcCoeff(float sigma, float& ap[], float& bp[], float& an[], float& bn[]);
任何人都可以告诉我可能是什么问题？我也试过了
void calcCoeff(float sigma, float &ap[5], float &bp[5], float &an[5], float &bn[5]);
谢谢...
我知道它太早了,但我升级到OSX mavericks并且我无法使用Homebrew安装opencv.
==> Installing dependencies for opencv: cmake, pkg-config, libpng
==> Installing opencv dependency: cmake
==> Downloading http://www.cmake.org/files/v2.8/cmake-2.8.12.tar.gz
######################################################################## 100.0%
==> ./bootstrap --prefix=/usr/local/Cellar/cmake/2.8.12 --system-libs --no-system-libarchive --datadir=/shar
==> make
==> make install
Warning: Could not link cmake. Unlinking...
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
You can try again using `brew link cmake'
Possible conflicting files are:
/usr/local/bin/ctest -> /usr/local/Cellar/cmake/2.8.10.2/bin/ctest
/usr/local/bin/cpack -> /usr/local/Cellar/cmake/2.8.10.2/bin/cpack
/usr/local/bin/cmakexbuild -> /usr/local/Cellar/cmake/2.8.10.2/bin/cmakexbuild
/usr/local/bin/cmake -> /usr/local/Cellar/cmake/2.8.10.2/bin/cmake
/usr/local/bin/ccmake …我试图使用grep打印关键字后的所有内容,但命令返回整行.我使用以下内容:
grep -P (\skeyword\s)(.*)
示例行是:
abcdefg keyword hello, how are you.
结果应该是,hello, how are you但它给出了整行.我在这里做错了吗？
When running the command jupyter notebook, I am getting the following error:
Traceback (most recent call last):
File "/usr/local/bin/jupyter-notebook", line 6, in <module>
from notebook.notebookapp import main
File "/usr/local/lib/python3.5/dist-packages/notebook/notebookapp.py", line 47, in <module>
from zmq.eventloop import ioloop
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/__init__.py", line 3, in <module>
from zmq.eventloop.ioloop import IOLoop
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/ioloop.py", line 21, in <module>
from tornado import ioloop
File "/usr/local/lib/python3.5/dist-packages/tornado/ioloop.py", line 45, in <module>
from tornado.concurrent import (
File "/usr/local/lib/python3.5/dist-packages/tornado/concurrent.py", line 175, in <module>
future: Union["futures.Future[_T]", "Future[_T]"], value: _T
File …我在OpenCV中创建了以下高斯内核,并将其与OpenCV的GaussianBlur函数进行了比较.但是,我得到的是黑色图像,而不是平滑的图像.有人可以对此有所了解吗？
Mat src, dst1,dst2;
Mat gaussiankrnl(3,3,CV_32F);
Point anchor;
double delta;
int ddepth;
anchor = Point( -1, -1 );
delta = 0;
ddepth = -1;
src = imread("coins.pgm");
gaussiankrnl.at<double>(0,0) = 1/16;
gaussiankrnl.at<double>(0,1) = 2/16;
gaussiankrnl.at<double>(0,2) = 1/16;
gaussiankrnl.at<double>(1,0) = 2/16;
gaussiankrnl.at<double>(1,1) = 4/16;
gaussiankrnl.at<double>(1,2) = 2/16;
gaussiankrnl.at<double>(2,0) = 1/16;
gaussiankrnl.at<double>(2,1) = 2/16;
gaussiankrnl.at<double>(2,2) = 1/16;
filter2D(src, dst1, ddepth , gaussiankrnl, anchor, delta, BORDER_DEFAULT );
GaussianBlur(src, dst2, Size(3,3), 1.0);
imshow("result1", dst1 );
imshow("result2", dst2 );
cvWaitKey(0);
return 0;
我有一个像下面这样的熊猫数据框:
col1, col2, label
a, b , cat
b, b1, , mouse
.
.
.........., elephant
.........., mouse
和value_counts标签栏:
df.dataframe.value_counts:
cat: 7599
mouse: 6458
dog: 5100
elephant: 5000
我想随机从每个标签类别中选择至少N行,以便我的value_counts变为:
cat: N
mouse: N
dog: N
elephant: N
有这种做法的"pandoic"方式吗？
我有一个如下的单词列表:
[w1, w2, w3, w4] (N字).
我想得到的是从左开始的组合:
w1, w1w2, w1w2w3, w1w2w3w4, w2, w2w3, w2w3w4, w3, w3w4, w4
有这样做的pythonic方式吗？
要在python中生成3个(或更多)数字的所有排列,可以使用itertools.permutations.如何分批生成两个组合.
对于前者 :输入数字列表:[1, 2, 3]
和输出:[1,2], [2,3], [1,3]