operation

./sysroot.sh: Operation not permitted

由 生来就可爱ヽ(ⅴ＜●) 提交于 2019-12-10 17:39:55
问题 im trying to install the cydia source code. $ git clone git://git.saurik.com/cydia.git $ cd cydia but when i typing "./sysroot.sh" i got this error: -bash: ./sysroot.sh: /usr/bin/env: bad interpreter: Operation not permitted what the problem? 回答1: My guess would be that the filesystem you are trying to run the script from is mounted using the "noexec" option. The interpreter inside of a shebang does not need to be in your $PATH, since an absolute path is specified. Try running your script by

Why can't I use Set:union() instead of Set.union?

由 佐手、 提交于 2019-12-10 14:58:43
问题 I am learning Lua and I would rather use the colon ( : ) for methods. Unfortunately, it's not working everywhere. See my code: Set= {} local mt= {} function Set:new(m) local set= {} setmetatable(set,mt) for a,b in pairs (m) do set[b]=true end return set end function Set.union(a,b) local res=Set:new ({}) for k in pairs (a) do res[k]=true end for k in pairs (b) do res[k]=true end return res end mt.__add=Set.union -- why Set:union() is not working here ? s1=Set:new {22,55,77} s2=Set:new {2,5,3}

floating-point operations with bash

由 淺唱寂寞╮ 提交于 2019-12-09 10:54:44
问题 how can I transform the string "620/100" into "6.2" in a bash script The context of my question is about image processing. EXIF data are coding the focal length in fractional format, while I need the corresponding decimal string. Thanks for helping, Olivier 回答1: Use bc -l bc -l <<< "scale=2; 620/100" 6.20 OR awk: awk 'BEGIN{printf "%.2f\n", (620/100)}' 6.20 回答2: bash doesn't support floating point. You could use bc : $ echo "50/10" | bc -l 5.00000000000000000000 $ echo "scale=1; 50/10" | bc

A loopless 3D matrix multiplication in python

由 坚强是说给别人听的谎言 提交于 2019-12-09 04:30:44
问题 I am looking to do the following operation in python (numpy). Matrix A is M x N x R Matrix B is N x 1 x R Matrix multiply AB = C, where C is a M x 1 x R matrix. Essentially each M x N layer of A (R of them) is matrix multiplied independently by each N x 1 vector in B. I am sure this is a one-liner. I have been trying to use tensordot(), but I that seems to be giving me answers that I don't expect. I have been programming in Igor Pro for nearly 10 years, and I am now trying to convert pages of

Multiply vector elements by a scalar value using STL

由 本小妞迷上赌 提交于 2019-12-08 22:42:00
问题 Hi I want to (multiply,add,etc) vector by scalar value for example myv1 * 3 , I know I can do a function with a forloop , but is there a way of doing this using STL function? Something like the {Algorithm.h :: transform function }? 回答1: Yes, using std::transform : std::transform(myv1.begin(), myv1.end(), myv1.begin(), std::bind(std::multiplies<T>(), std::placeholders::_1, 3)); Before C++17 you could use std::bind1st() , which was deprecated in C++11. std::transform(myv1.begin(), myv1.end(),

Cassandra CQLSH OperationTimedOut error=Client request timeout. See Session.execute[_async](timeout)

由 夙愿已清 提交于 2019-12-06 17:40:58
问题 I want to transfer data from one Cassandra cluster (reached via 192.168.0.200) to another Cassandra cluster (reached via 127.0.0.1). The data is 523 rows but each row is about 1 MB. I am using the COPY FROM and COPY TO command. I get the following error when I issue the COPY TO command: Error for (8948428671687021382, 9075041744804640605): OperationTimedOut - errors={ '192.168.0.200': 'Client request timeout. See Session.execute[_async](timeout)'}, last_host=192.168.0.200 (will try again

Python odd operation?

由 巧了我就是萌 提交于 2019-12-06 16:24:05
Can somebody please explain me why the code below behaves like it does? (It's Python in command line on Windows7 x64) >>>2.22 + 0.22 2.44000000000000004 >>>(222+22)/100 2.44 Floating point operations are limited in percision, and in python the limitations are well documented. You can read about it here All floating point math is like this and is based on the IEEE standard. Floating point oprations are known to cause errors. http://en.wikipedia.org/wiki/IEEE_floating_point Use the decimal module if you want precise calculations. this is due to the data format. 2.22 + 0.22 != 2.44 // both are

How do I perform a deletion of the kth element on a min-max heap?

由 空扰寡人 提交于 2019-12-06 14:19:48
问题 A min-max heap can be useful to implement a double-ended priority queue because of its constant time find-min and find-max operations. We can also retrieve the minimum and maximum elements in the min-max heap in O(log 2 n) time. Sometimes, though, we may also want to delete any node in the min-max heap, and this can be done in O(log 2 n) , according to the paper which introduced min-max heaps: ... The structure can also be generalized to support the operation Find(k) (determine the kth

Dot Product in Python without NumPy

由 别来无恙 提交于 2019-12-06 03:44:18
问题 Is there a way that you can preform a dot product of two lists that contain values without using NumPy or the Operation module in Python? So that the code is as simple as it could get? For example: V_1=[1,2,3] V_2=[4,5,6] Dot(V_1,V_2) Answer: 32 回答1: Without numpy, you can write yourself a function for the dot product which uses zip and sum . >>> def dot(v1, v2): ... return sum(x*y for x,y in zip(v1,v2)) ... >>> dot([1,2,3], [4,5,6]) 32 来源： https://stackoverflow.com/questions/35208160/dot

Can I convert a string to a math operation in java?

由 主宰稳场 提交于 2019-12-06 00:41:52
问题 can I convert a string like "3*3+3" to math operation in java?? 回答1: Evaluate it is as JavaScript using ScriptEngine String xyz = "3*3+3"; ScriptEngineManager manager = new ScriptEngineManager(); ScriptEngine se = manager.getEngineByName("JavaScript"); Object result = se.eval(xyz); Reference: Documentation 回答2: There is no built-in function for that, you would have to implement a parser. However you could also look up for ready project, such as: http://sourceforge.net/projects/jep/ or http:/
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