In my current directory I have a file mini.m
function ret = mini(x)
ret = x(1);
for i = 2:length(x),
if x(i) < ret,
ret = x(i);
end;
end;
endfunction
Then I run
>> octave
>> edit mini.m
My arrow buttons are not working property. Instead of navigating the cursor, the arrow buttons type random characters over my file, like this.
OBOCCOCOCCOUnOCOCCOC ORtO= Miniddddddde
fdOCXCOCOC
RetOOCOC# Octave 4.0.0, Sun Sep 27 01:01:33 2015 EDT <yanshen#Sams-MacBook.local>Or i = 2:length(x),
if x(i) < ret,
ret = x(i);
end;
end;
endfunction
Anyone has an idea of what's going on? Thank you!
I ended up setting vim as my default editor for octave by following instructions at http://wiki.octave.org/Vim.
I have Octave 4.0.0. I added the following lines to my ~/.octaverc file:
edit mode sync
edit home .
EDITOR('vim > /dev/tty 2>&1 < /dev/tty %s')
Related
I have code similar to the one below, where a function with a parameter depending on the loop iteration is plotted after every iteration. I would like to save the plot with the name trigplot_i.ps where i is the iteration number, but don't know how.
I have tried trigplot_"i".ps but didn't work, and have not been able to find how to cast i to a string either.
I'm a beginner so any help is very welcome.
f(x) := sin(x);
g(x) := cos(x);
for i:1 thru 10 do
(plot2d([i*f(x), i*g(x)], [x,-5,5],[legend,"sin(x)","cos(x)"],
[xlabel,"x"],[ylabel,"y"],
[ps_file,"./trigplot_i.ps"],
[gnuplot_preamble,"set key box spacing 1.3 top right"])
);
code after edits gives an error:
f(x) := sin(x);
g(x) := cos(x);
for i:1 thru 10
do block([myfile],
myfile: sconcat("./trigplot_", i, ".ps"),
printf (true, "iteration ~d, myfile = ~a~%", myfile),
plot2d([i*f(x), i*g(x)], [x,-5,5],[legend,"sin(x)","cos(x)"],
[xlabel,"x"],[ylabel,"y"],
[ps_file, myfile],
[gnuplot_preamble,"set key box spacing 1.3 top right"])
);
error:
"declare: argument must be a symbol; found "./trigplot_1.ps
-- an error.
To debug this try: debugmode(true);"
Looks good. To construct a file name, try this: sconcat("./trigplot_", i, ".ps") or also you can try: printf(false, "./trigplot_~d.ps", i). My advice is to make that a separate step in the loop, and then you can use it in the call to plot2d, e.g.:
for i:1 thru 10
do block ([myfile],
myfile: sconcat("./trigplot_", i, ".ps"),
printf (true, "iteration ~d, myfile = ~a~%", i, myfile),
plot2d (<stuff goes here>, [ps_file, myfile], <more stuff>));
EDIT: Fixed a bug in printf (omitted argument i).
I would like to plot a sawtooth function in Octave. I know that I can use the command "sawtooth(t)" but I don't have the package so I created the following function.
function x = pieceWise2bis(t)
x = zeros (size (t));
ind1 = t >= 10 & t < 13;
x(ind1) = +20;
ind2=t >= 13 & t < 16;
x(ind2) = -20;
ind3=t >= 16 & t < 19;
x(ind3) = +20;
ind4=t >= 19 & t < 22;
x(ind4) = -20;
endfunction
When I plot this function I don't get the result I'm looking for because I want a real sawtooth function and not a periodic function with crenels like that.
COuld someone tell me how I could adapt my code ?
Thank you
It appears that the usual way to load sawtooth, by installing signal which requires control.... is not working, in any case you are way better off writing this yourself. Here's one of many ways to do it:
clear; %% this line tells octave the remainder is more than just a func.
## usage: ST = sawtooth (time)
function ST = sawtooth (time)
ST=rem(time,2*pi)/2/pi;
endfunction
time=linspace(0,20,101); % second line of main program (clear is 1st)
PriSawtooth=sawtooth(time);
plot(time,PriSawtooth,'linewidth',1)
I have a feeling there is something obvious I'm missing, but my searches are coming up fruitless thus far.
I am trying to use a tcl/expect script to start up a tclsh interactive shell, add a procedure for easily reloading utilities for testing, and then return normal control to me.
So far, the one way I've discovered to make a tcl interactive shell "usable" is to start it with "rlwrap" so that I can use arrow keys, etc.
So I tried the following script and something about rlwrap is causing previous output to be dumped to stdout when the interact command is hit.
Is there something I can do to make this not happen?
Code:
package require Expect
puts "Tcl version : [info tclversion]"
puts "Expect version: [exp_version]"
log_user 0
spawn -noecho rlwrap tclsh
# Create procedure to easily reload utilites after changes have been made
expect "% "
send {
proc reload {} {
# Procedure to reload utility source easily for testing
}
}
# Source utilities
expect "% "
send "reload\r"
send_user "\nUse 'reload' procedure to re-source utility files\n\n"
log_user 1
interact
Output:
Tcl version : 8.4
Expect version: 5.43.0
Use 'reload' procedure to re-source utility files
proc reload {} {
# Procedure to reload utility source easily for testing
}
% reload
%
You can that for some reason it's echoing the proc definition and the entering of the reload command. This occurs as soon as interact occurs. If I replace interact with "exit" I do not see any of this output.
Of course the output I'm hope to see would be this:
Tcl version : 8.4
Expect version: 5.43.0
Use 'reload' procedure to re-source utility files
%
If you don't mind to compile a small C program yourself, you could use this:
#include <tcl.h>
#ifdef WIN32
#ifdef UNICODE
#define WIN32_UNICODE
#endif
#endif
int TclSHI_Main(Tcl_Interp*);
static int g_argc;
#ifdef WIN32_UNICODE
#define Tcl_NewStringObj Tcl_NewUnicodeObj
static wchar_t*** g_argv;
void wmain(int argc, wchar_t **argv) {
#else
static char*** g_argv;
void main(int argc, char **argv) {
#endif
g_argc = argc;
g_argv = &argv;
Tcl_FindExecutable(argv[0]);
Tcl_Main(1, argv, TclSHI_Main);
}
int TclSHI_Main(Tcl_Interp* interp) {
Tcl_Obj* lobj;
int i;
if (g_argc > 1) {
Tcl_SetVar2Ex(interp, "argv0", NULL, Tcl_NewStringObj((*g_argv)[1], -1), TCL_GLOBAL_ONLY);
}
lobj = Tcl_NewObj();
Tcl_IncrRefCount(lobj);
for (i = 2; i < g_argc; i++) {
Tcl_ListObjAppendElement(interp, lobj, Tcl_NewStringObj((*g_argv)[i], -1));
}
Tcl_SetVar2Ex(interp, "argv", NULL, lobj, TCL_GLOBAL_ONLY);
Tcl_DecrRefCount(lobj);
Tcl_SetVar2Ex(interp, "argc", NULL, Tcl_NewIntObj(g_argc - 2), TCL_GLOBAL_ONLY);
if (g_argc > 1) {
Tcl_Eval(interp, "source $argv0");
}
return TCL_OK;
}
I tested it on windows (CL) and linux (GCC).
To compile it with gcc I used gcc TclSH.c -o TclSHI -ltcl8.6
On windows I used Visual Studio.
It tells Tcl that it did not receive any arguments (Tcl_Main(1,...)), but populates the new interp with this arguments and sources the file. After this step it will always show the prompt (it never received any arguments, right?).
There is a small problem with your expect solution, if you specify any arguments, Tcl would execute that script, and never show the prompt.
Also note that I'm a novice C programmer, so this solution might not be bullet proof.
What you want to do is to wait for an unambiguous marker that indicates that the subordinate process is ready.
# ... your script as above ...
expect "% "
#### NEW STUFF STARTS ####
send "reload;puts READY\r"
expect "READY\r"
# Note that we need to fake the prompt; c'est la vie
send_user "\nUse 'reload' procedure to re-source utility files\n\n% "
# Now start doing things!
log_user 1
interact
Or at least that works when I try with a subordinate process, but I wasn't using rlwrap in the mix so that might change things…
I have a very short test file:
let print_backtrace () = try raise Not_found with
Not_found -> Printexc.print_backtrace stdout;;
let f () = print_backtrace (); Printf.printf "this is to make f non-tail-recursive\n";;
f ();
I compile and run:
% ocamlc -g test.ml
% OCAMLRUNPARAM=b ./a.out
Raised at file "test.ml", line 1, characters 35-44
this is to make f non-tail-recursive
Why isn't f listed in the stack trace? How can I write a function that will print a stack trace of the location it's called from?
The documentation for Printexc.print_backtrace says:
The backtrace lists the program locations where the most-recently raised exception was raised and where it was propagated through function calls.
It actually seems to be doing the right thing. The exception hasn't been propagated back through f.
If I move the call to Printexc.print_backtrace outside the call to f, I see a full backtrace.
$ cat test2.ml
let print_backtrace () = raise Not_found
let f () = let res = print_backtrace () in res ;;
try f () with Not_found -> Printexc.print_backtrace stdout
$ /usr/local/ocaml312/bin/ocamlc -g test2.ml
$ OCAMLRUNPARAM=b a.out
Raised at file "test2.ml", line 1, characters 31-40
Called from file "test2.ml", line 3, characters 21-39
Called from file "test2.ml", line 5, characters 4-8
Here is the code to do what I suggested. I recommend using ocamldebug if at all possible, this code is much too tricky. But it works on my system for this simple example.
let print_backtrace () =
match Unix.fork () with
| 0 -> raise Not_found
| pid -> let _ = Unix.waitpid [] pid in ()
let f () =
begin
print_backtrace ();
Printf.printf "after the backtrace\n";
end
;;
f ()
Here is a test run.
$ /usr/local/ocaml312/bin/ocamlc unix.cma -g test3.ml
$ OCAMLRUNPARAM=b a.out
Fatal error: exception Not_found
Raised at file "test3.ml", line 3, characters 17-26
Called from file "test3.ml", line 8, characters 4-22
Called from file "test3.ml", line 14, characters 0-4
after the backtrace
I realized that because of the uncaught exception, you don't really have any control over the way the child process exits. That's one reason this code is much too tricky. Please don't blame me if it doesn't work for you, but I hope it does prove useful.
I tested the code on Mac OS X 10.6.8 using OCaml 3.12.0.
Best regards,
Is there a command like 'scanf' in GNU Octave to read the user inputs from the keyboard?
Yes, the function is called input. A simple example:
octave-3.2.4:3> x = input("Enter a number: ")
Enter a number: 25
x = 25
See the documentation for details, like overriding the default parsing behavior.
In GNU Octave, How to get user input line, aka open stdin:
Make a file called: test.m
Put this code in there:
line = fgetl(stdin);
line
Run it like so:
octave test.m
Enter in some words then press Enter
5 abc 7
The program responds:
line = 5 abc 7
Read more about function: fgetl https://www.gnu.org/software/octave/doc/interpreter/Line_002dOriented-Input.html#XREFfgetl
There is scanf function in addition to input function.
For example:
% Get a number
x = scanf("%d", "C");
% Get a vector of size 5
for i=1:5
x(i) = scanf("%d", "C");
end
% Get a matrix
printf("Enter a 3x2 matrix \n ");
for i=1:3
for j=1:2
n(i,j) = scanf("%d", "C");
end
end
disp(n)