I have a rather dull Fortran program that are used by students for some heavy calculations and I thought the program might be a little more interesting if I could add some sounds here and there. Is there any utility to generate sounds that is callable from a Fortran program? I would like to call a routine with for example a selection of MP3 files.
I do not like programs which beeps and plings in general but this is a kind of last resort to keep the students alert ...
I'd go with C library (e.g. How to play MP3 files in C?).
I'd create shared lib with your routine (e.g. code playing some sort of mp3 list) and called it from Fortran code.
Question is, whether this is what you are looking for.
It may be interesting to try the system call together with a command-line tool, e.g.
program main
implicit none
integer i
character(100) :: message(3)
message(1) = "hi"
message(2) = "yo"
message(3) = "done!"
do i = 1, 3
call system( "say " // trim( message(i) ) )
enddo
end
which says any message via speech synthesis on Mac OSX. A similar thing may be achieved for MP3 files with some audio commands (on Windows, Mac, and Linux). This demo seems to be using such an approach (Note: music starts from the page!).
Related
I have looked extensively in the net, yet not found exactly what I want.
I have a big simulation program that outputs results in a MATLAB M-file (let's call it res.m) and I want to plot the results visually.
I want to start the simulation with C++ many times in a row and therefore want to automatize the plotting of the results.
I come up to two options:
Execute from C++ an Octave or MATLAB script that generates the graph.
-> Haven't found anyone who managed to do so
Use the Octave source files to read the res.m file and output them after with whatever plotting C++ tool.
-> Theoretically possible but I get lost in those files
Is someone able to solve this? Or has a better, easier approach?
The answer is to execute through the terminal.
I didn't manage to actually run a octave script from my c++ program directly, but there is a way around messing with/through the terminal and a extra Octave file. I used in my cpp:
string = "octave myProgr.m"
const char *command = str.c_str();
system(command);
myProgr.m is the script that plots the res.m file
Is there any possibility to launch an external program from Fortran and write something to this programs standard input?
I know e.g. of gfortran's SYSTEM but there is no such option.
As you have noticed, GFortran does not have anything like the pipe()/fork()/exec() functions builtin.
If you're on Linux or some other Unix-like system you could do something like
execute_command_line("mkfifo /path/to/fifo")
The mkfifo command creates a named pipe, that is, a pipe that also has a name in the filesystem.
open(newunit=plot_unit, file="/path/to/fifo", access="stream", format="formatted")
execute_command_line("gnuplot < /path/to/fifo")
So the idea is that you can then open the FIFO like a normal external unit in GFortran, then execute gnuplot with standard input connected to the FIFO.
You might need to exchange the order of #2 and #3 in case this deadlocks. But some minor variation of the above should work (I've used it to connect to one Fortran program from another).
Firstly, if you're using a relatively recent compiler you should be able to use execute_command_line (part of the f2008 spec) instead of system (compiler extension). This launches a command using the C library's system call which uses the sh shell on nix and cmd.exe on Windows (see here). As such you can use standard input redirection type approaches to connect to stdin of the launched program, but it may not be suitable for more complicated use.
The following example shows a simple example
program stdIn
implicit none
character(len=20) :: cmd, args
character(len=50) :: fullcmd
cmd = "bc"
args = "1+2"
fullcmd = cmd//" <<< "//args
print*,"Running ",fullcmd
call execute_command_line(fullcmd)
end program stdIn
Which should output
Running bc <<< 1+2
3
I have a program in Fortran that calculates a file, say, named
wvfunc3d.dat
which I want to visualize with Gnuplot in real time during the execution of my program. After the code that creates this file, I put in my program a string
jret=SYSTEM('gnuplot wf3d.plt')
the script file wf3d.plt has the only string and looks like:
splot 'wvfunc3d.dat' w l
All of this really draws a plot I want to see, but, as is well known, it immediately disappears. I know, there is an option to avoid the closing of the window,
jret=SYSTEM('gnuplot -persist wf3d.plt')
that lets my plot not to disappear, but then the execution of the Fortran program also freezes until I close the window with the graph.
So, I want the plot to persist until I have new data, to be automatically updated after a new call of a command in Fortran, but I also need my program to run calculations! Is there a way to solve this problem? I use Windows XP.
I think you may be able to use EXECUTE_COMMAND_LINE instead of system to achieve what you want. This allows you to include a wait option which when set to .false. allows the fortran code to keep running. You can then add a sleep and reread to your gnuplot script (e.g. sleep 1 and reread) as suggested in this post.
If this doesn't work, you could consider a multi-threaded strategy ( openMP or mpi in fortran). Personally, I usually just run gnuplot at the same time and trigger an update of the plotted data by pressing the a key. I use linux so cannot test it for windows but a minimal example which works for me is,
program gnuplot
implicit none
logical :: gnuplot_open = .false.
integer :: i,t,N,redraw
real(kind(0.d0)),dimension(:),allocatable :: x,y
real(kind(0.d0)),parameter:: pi=4.d0*atan(1.d0)
N = 1000
allocate(x(N),y(N))
redraw = 100
do t = 1,300000
do i=1,N
x(i) = 6.d0*i/N*pi
y(i) = sin(x(i)+t*0.2)
enddo
if (mod(t,redraw) .eq. 0) then
open(1,FILE='./tempout',status='replace')
do i=1,N
write(1,*) x(i),y(i)
enddo
close(1,status='keep')
endif
if (.not. gnuplot_open) then
call execute_command_line('gnuplot --persist plot_tempout', wait=.false.)
gnuplot_open = .true.
endif
enddo
end program gnuplot
and plot_tempout is,
plot 'tempout' u 1:2 w l
pause 0.1
reread
Ed, thank you very much for your thorough reply. I will try to work on it.
Before encountering this problem I was able to easily draw the plots of small enough files using a cycle directly in gnuplot. Something like this:
do for [i=1:100500] {plot 'littldat.dat' w l; pause 3}
that did it well. But when I tried to do this with large file, it was very often caught read by gnuplot in the moment it was not completed yet: I had either a full plot or a plot of a part of my data, and it was not good. Because of this I began to seek for the way to do it by the means of programming language.
Before you answered I finally found a very simply, though not very elegant solution: you write data to a temporary file and then, once it is completed, give it the final name to be read by gnuplot. So, gnuplot reads either old data, or new ones, but never an incomplete file. It results to be something like this in Fortran:
open(1,file='donnees_temp.dat')
write(1,*)x,y,z
close(1)
call rename ('donnees_temp.dat','donnees.dat')
and, in Gnuplot I used a cycle like the one above:
do for [i=1:100500] {splot 'donnees.dat' w l; pause 5}
so it works, and the program executes.
This one's going to take a bit of explaining. Please bear with me.
What I Have
I have in my possession some Fortran source code and some binaries that have been compiled from that code. I did not do the compilation, but there is a build script that suggests G77 was used to do it.
As well as the Fortran stuff, there is also some Java code that provides users with a GUI "wrapper" around the binaries. It passes information between itself and the binaries via their input/output/error pipes. The Java code is very messy, and this way of doing things adds a lot of boilerplate and redundancy, but it does the job and I know it works.
What I Need
Unfortunately, I'd like to make some changes:
I want to create a new Python wrapper for the binaries (or, more precisely, extend an existing Python program to become the new wrapper).
I want to be able to compile the Fortran code as part of this existing program's build process. I would like to use gfortran for this, since MinGW is used elsewhere in the build and so it will be readily available.
The Problem
When I compile the Fortran code myself using gfortran, I cannot get the resulting binaries to "talk" to either the current Java wrapper or my new Python wrapper.
Here are the various ways of printing to the console that I have tried in the Fortran code:
subroutine printA(message)
write(6,*) message
end
subroutine printB(message)
write(*,*) message
end
subroutine printC(message)
use iso_fortran_env
write(output_unit,*) message
end
There are also read commands as well, but the code doesn't even get a change to execute that part so I'm not worrying about it yet.
Extra Info
I have to call gfortran with the -ffixed-line-length-132 flag so that the code compiles, but apart from that I don't use anything else. I have tried using the -ff2c flag in the vague hope that it will make a difference. It doesn't.
This stackoverflow post is informative, but doesn't offer me anything that works.
The relavant manual page suggests that printA should work just fine.
I'm working on Windows, but will need this to be multi-platform.
Juse in case you're intested, the Java code uses Runtime.getRuntime().exec("prog.exe") to call the binaries and then the various "stream" methods of the resulting Process object to communicate with them. The Python code uses equivalents of this provided by the Popen object of the subprocess module.
I should also say that I am aware there are alternatives. Rewriting the code in Python (or something else like C++), or making amendments so that is it can be called via F2Py have been ruled out as options. Using g77 is also a no-go; we have enough dependencies as it is. I'd like to be able to write to / read from the console properly with gfortran, or know that it's just not possible.
Hard to say without seeing more details from your Fortran and Python codes. The following pair of code works for me (at least under Linux):
Fortran program repeating its input line by line prefixed with line number:
program test_communication
use iso_fortran_env, stdout => output_unit, stdin => input_unit
implicit none
character(100) :: buffer
integer :: ii
ii = 1
do while (.true.)
read(stdin, *) buffer
write(stdout, "(I0,A,A)") ii, "|", trim(buffer)
flush(stdout)
ii = ii + 1
end do
end program test_communication
Python program invoking the Fortran binary. You can feed it with arbitrary strings from the console.
import subprocess as sub
print "Starting child"
proc = sub.Popen("./a.out", stdin=sub.PIPE, stdout=sub.PIPE)
while True:
send = raw_input("Enter a string: ")
if not send:
print "Exiting loop"
break
proc.stdin.write(send)
proc.stdin.write("\n")
proc.stdin.flush()
print "Sent:", send
recv = proc.stdout.readline()
print "Received:", recv.rstrip()
print "Killing child"
proc.kill()
I have a simple C++ program that takes in inputs and outputs some string. Like this:
$ ./game
$ what kind of game? type r for regular, s for special.
$ r
$ choose a number from 1 - 10
$ 1
$ no try again
$ 2
$ no try again
$ 5
$ yes you WIN!
Now I want to write a c++ program can runs this c++ program and plays the game automatically without user input and then outputs it to a file or standard output.
Running it would look like this:
./program game r > outputfile
game is the game program, r for playing regular style.
How should I do this? The main reason I need this program is that I want to do automatic testing for a much bigger program.
You could use std::system from <cstdlib>:
std::system("game r > outputfile");
The return value is ./program's, the sole argument must be of type char const *.
There is no standard way to run a program and feed it standard input, though. Judging by your command line, you're on some Unix variant where popen from <stdio.h> should work:
FILE *sub = popen("game r > outputfile", "w");
then write to sub with the stdio functions and read outputfile afterwards.
(But for simple testing, I'd recommend implementing the core logic of your program as a set of functions/classes that can be run by a custom main function in a loop; or pick your favorite scripting language to handle this kind of thing.)
I'd be more efficient to add a caller function to your main source and have it control looping, logging, and feeding input. It would also not require system calls or other magic to pull off. Being a game programmer, we have our games play themselves as much as possible to help with debugging, and almost always this is done via internal code, not through external scripting or system calls. It makes it easier to feed viable input as well.
This scenario cries out for a "script", IMHO.
Bash, Perl, Python - you name it.
SIMPLEST CASE:
Just write a bash script to call ./program game r > outputfile.
Or ./program game r < test_input.txt > test_output.txt
For more advanced scenarios, you might want to look at "expect".
You might also want to look at "STAF", which might be a great way to "automate your automated tests":
http://staf.sourceforge.net/current/STAFFAQ.htm