r - Convert a matrix to a 1 dimensional array -

-

i have matrix (32x48).

how can convert matrix single dimensional array?

if we're talking data.frame, should ask variables of same type? if that's case, can use rapply, or unlist, since data.frames lists, deep down in souls...

 data(mtcars)  unlist(mtcars)  rapply(mtcars, c) # stupid , pointless, , slower

Comments

Post a Comment

Popular posts from this blog

C#: Application without a window or taskbar item (background app) that can still use Console.WriteLine() -

-
i'm trying create application adheres following: no taskbar no console or form window can utilize console.writeline() . (i.e. if executes app command prompt write console.) the problem if create windows form (or wpf) application can have there no taskbar, console or window show up, console.writeline() nothing. if create console app, writes console, can't figure out how hide (and if did hide it, write command prompt window?)... how do this? just create standard console application. callers responsibility hide window caused program (from how run c# console application console hidden ): system.diagnostics.processstartinfo start = new system.diagnostics.processstartinfo(); start.filename = dir + @"\myprocesstostart.exe"; start.windowstyle = system.diagnostics.processwindowstyle.hidden;
Read more

ruby - When to use an ORM (Sequel, Datamapper, AR, etc.) vs. pure SQL for querying -

-
a colleague of mine designing sql queries 1 below produce reports, displayed in excel files through external data query. @ present, reporting processes on db required (no crud operations). i trying convince him better use ruby orm in order able display data in rails/sinatra app. despite obvious advantages in displaying data, advantages there him in learning use orm sequel or datamapper? the sql queries writing quite complex, , being relatively new sql, complains time-consuming , confusing. possible write extremely complex queries orm? , if so, suitable(i have heard sequel legacy dbs)? , advantages of learning ruby , using orm versus sticking plain sql, in making complex database queries? i'm datamapper maintainer, , think complex reporting should use sql. while think someday we'll have dsl provides power , conciseness of sql, i've seen far requires write more ruby code sql complex queries. rather maintain 5 line sql query 10-15 lines of ruby code desc...
Read more

c++ - Convert big endian to little endian when reading from a binary file -

-
this question has answer here: how convert between big-endian , little-endian values in c++? 28 answers i've been looking around how convert big-endian little-endians. didn't find solve problem. seem there's many way can conversion. anyway following code works ok in big-endian system. how should write conversion function work on little-endian system well? this homework, since systems @ school running big-endian system. it's got curious , wanted make work on home computer also #include <iostream> #include <fstream> using namespace std; int main() { ifstream file; file.open("file.bin", ios::in | ios::binary); if(!file) cerr << "not able read" << endl; else { cout << "opened" << endl; int i_var; double d_var; while(!file.eof()) {...
Read more