I have a C++ function that given 3 integers and a string, makes some statical tests from a matrix read from a txt file and creates as output a txt file called as the input string.
I would like to place this program in a matlab scrips that loops inside a cell array A made of sparse matrices in the following way:
formatSpec = string('Validated_edge_layer%d_time%d');
for k=1:size(A,1)
for j=1:size(A,2)
n1=size(A{k,j},1);
n2=size(A{k,j},2);
e=nnz(A{k,j});
write_to_txt(A{k,j};
string=sprintf(formatSpec,k,j);
*** HERE I WOULD LIKE TO CALL THE C++ FUNCTION WITH INPUTS n1,n2,string ***
end
end
So basically inside the loop matlab evaluates the inputs of the C++ function and writes within each iteration a txt files that is then read by the C++ function (the files gets overwritten so that the C++ function can read a new set of variables). At the end of the loop I would like to have something like 120 txt files each named differently and in an order that follows the cell array organization.
Is this task possible? I know that something called MEX files can be used but I know nothing about it.
I hope that I have explained myself clearly. Thanks.
Related
I have a .lua file as follows:
timeout = 3000
index = 15
function Test()
A(index, timeout)
B()
end
Test()
A and B fuctions are implemented in the c++. It will be excuted with a 'luaL_dofile(L, "test.lua");' in c++.But the timeout and the index will change at different times.
The question is how to modify the params in real time?
I'm going to write two c++ programs.First one is to sent .lua string to the sencond one. The second c++ program implemets the A and B and will dofile the lua script. But the timeout and the index will changes very often. How to do that? My solution is to parse the index and timeout string ,then write the current value to the file in the first c++ program.Any better solution?
Instead of modifying a lua script over and over to call A with different arguments, you should probably just list all arugments in a single script.
local listOfIndices = {1,5,23,124,25,}
local timeout = 3000
for _,index in ipairs(listOfIndices) do
A(index, timeout)
B()
end
Otherwise having 10000 different indices will result in 10000 file write and read operations.
If you're on Windows you might want to give this a read https://learn.microsoft.com/de-de/windows/win32/ipc/interprocess-communications?redirectedfrom=MSDN
I can think of better ways to have two programs communicate, than sending Lua scripts through files.
Also I'm not sure why you need two applications here, why not add whatever applicaton 2 does to application 1 as a library?
Hello I have been having trouble with my program I've created a list and I have the following program
Its goal is to Read the 5 variables inside the text file 5 variables in 5 different inputs
so I manage to correctly show the list inside the while loop since every time a line is read it's printed untill .eof(End Of File)
My goal is that I am trying to print the list OUTSIDE of the while Loop that has already read and printed those 5 variables 10x the problem is that it repeats the last entered 5 Variables in the list
I and repeats that 10x (size of the list)
I've also tried something like this inside the for loop which I found in here:
int ID=it->ID;
string NAME=it->NAME;
int SEMESTER=it->SEMESTER;
string DIRECTION=it->DIRECTION;
double GRADE=it->GRADE;
As if those are nodes but I am a starter with nodes as well as lists and it seems to have failed
When I look at the code you've provided, I see that in your for loop the a_student is used, which is not updated by/with the iterator. Basically you're not looping over the created student list.
Maybe try using std::for_each (cppreference) it will save you a lot of time:)
Godbolt example: https://godbolt.org/z/fQUhcr
The issue on the left column of code is that you are not de-referencing the iterator. You never set the a_students variable inside the loop, so why do you expect it to change on each iteration?
Write something like:
a_students = *it;
inside the loop. However there is a simpler way. Instead of manually handling the iterators, use:
for (auto a_students: s_stl_list)
{
// do something with each "a_students" which will be AUTOmatically the right type
}
I have a Fortran program that needs to read ASCII files, however the list of files sometimes includes a file of size 0. The program then crashes when trying to read this file. I have not find any way so far that will allow me to flag such a file.
I have following READ statement in my code
read(10,220,END=320,ERR=195)parm(1:)
although I expect code to go to statement 195, or to statement 320, without crashing, it crashes
this is where the code crashes when the file size is zero, with the following messages
...
fmt: end of file
apparent state: unit 10 named junko.con
last format: (A)
lately reading sequential formatted external IO
I tried using the INQUIRE statement
inquire (unit=10,SIZE=nsize), but the program would not compile
the OPEN statement did not give any error when opening the zero size file, and the values of IOSTAT was the same, irrespective of the file size
As Ian noted, any modern Fortran compiler should have INQUIRE. A simple test of
program foo
integer sz
inquire(file='tmp.dat',size=sz)
print *, sz
end program foo
with an empty tmp.dat file sets sz=0.
I know how to do stuff with Lua states and what not but what i don't understand is how you would distribute the final program with a seperate lua file because say you have a .exe and a lua file in the same directory how would I make it so that it is all one executable like how Löve 2d uses
copy /b
to append the lua file to the Löve 2d interpreter so it can be distributed.
could someone possibly explain how this works.
many thanks
Blazing
You could embed the lua code directly into your C++ source in a raw string literal like so:
const auto lua_code = R"lua(
...lua code here...
)lua";
I have a problem related to passing arguments to a C++ compiled executable. The program emulate the behaviour of a particular inference engine: the setup of the engine is load at runtime from an XML file, and then I want to call it from command line with different input values.
The characteristic of the input are:
Every time that I call the program, the input structure is different, because the system itself is different.
The input is a set of couple {name, value}, one for each part of the system.
I have to separate the configuration XML from the input.
I call the program from a PHP or Node.js server, since it return a result that I expose to the outside through an API.
Input value are obtained from an HTTP post request.
By now I have tried these solutions:
Pass it from the command line ex: "./mysoftware input1 value1 input2 value2 ...etc". A little unconfortable, since I have up to 200 input.
Create a file with all the couples name,value and then call the program that parse the file and then destroy at the end. This is a bottleneck of performance for my API, because at every call I have to create and destruct a file.
Does anyone know a better way to approach this problem?
3. Pass the values to the program via the standard input stream and read them from std::cin inside your C++ program.