![]() You may also initialize the state vector from an arbitrary vector of length You can query the state of the random number generator using the form The arguments are handled the same as the arguments for eye. Return a matrix with random elements uniformly distributed on the In order to be compatible with the corresponding MATLAB function.Īlso for compatibility with MATLAB, return the second argument b Return a row vector with n elements logarithmically spaced from : logspace ( a, b) : logspace ( a, b, n) : logspace ( a, pi, n) Linspace transforms them to column vectors and returns a matrix whereĮach row is an independent sequence betweenįor compatibility with MATLAB, return the second argument ( limit) ![]() If one, or both, inputs are vectors, then The linspace function returns a row vector when both baseĪnd limit are scalars. Number of points is not specified, a value of 100 is used. ![]() Than limit, the elements are stored in decreasing order. If the number of elements is greater than one, then the endpoints baseĪnd limit are always included in the range. Return a row vector with n linearly spaced elements between : linspace ( base, limit) : linspace ( base, limit, n) The functions linspace and logspace make it very easy toĬreate vectors with evenly or logarithmically spaced elements. A row vector is alwaysĬonceptually the result is calculated as follows: Matrix then the columns of x are imagined to be stacked on top ofĮach other for purposes of the selection index. Second row, r(2,j), specifies the repeat count. R is a 2x N integer matrix specifying which elements to repeatĪnd how often to repeat each element. ForĬopying along more than two dimensions, specify the number of times to copyĪcross each dimension m, n, p, …, in a vector in theĬonstruct a vector of repeated elements from x. If n is not specified, form an m by m block matrix. But you can get the pointer to the array and since a pointer is an iterator, you can pass it into an algorithm.: repmat ( A, m) : repmat ( A, m, n) : repmat ( A, m, n, p …) : repmat ( A, ) : repmat ( A, )įorm a block matrix of size m by n, with a copy of matrix ( *) update: unique_ptr is not a container, so it won’t work with standard algorithms… at least out of the box. Is not a container, so it doesn’t work with standard algorithms( *) Has no pointers, iterators, so you can only invalidate it by swapĬompatibility with concepts and algorithms Vector may invalidate pointers and iterators when you have a reallocation O(n) time swap and move operations, where n is the number of elements in the arrayĮnsures pointers, references and iterators will never be invalidated while the object is live, even on swap() And some people get their arrays from other code that is known to return an array and that code isn’t going to be rewritten to return a vector or something.Īnd here’s a nice comparison for each technique: Use caseĭoes not allow resizing (unless you recreate the whole thing) Some people need a dynamically sized array, so std::array is out. Some people do not have the luxury of using std::vector, even with allocators. I got several interesting answers, and we can summarize them with the following quote: When I wrote my early blog post on smart pointers - C++ Smart Pointers Gotchas - C++ Stories, back in 2013, I also asked a question at Stack Overflow.Ĭ++ - Is there any use for unique_ptr with array? - Stack OverflowĪnd so far, it’s one of my most voted questions :) Let’s have a look at some possible use cases. I guess it’s much more convenient to use std::vector and pass it around than passing unique_ptr? Ok, we covered how to create pointers and even saw some recent updates in C++20… but should we even use it? ![]() The _for_overwrite functions allow for even 20x init speed up of the initialization code! See my premium article with a benchmark which is available for C++ Stories Premium/Patreon members. ![]()
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