Getting user inputs from the STDIN in Octave using input()? - octave

Can any please help me why am I getting this error on running the Octave(version 3.8.1) code below-
a = input("");
b = input("");
printf("%d", a+b);
./CandidateCode.m: line 1: syntax error near unexpected token ('
./CandidateCode.m: line 1:a = input("");'
Please help me in resolving this error.

If you run your Script CandidateCode.m from shell, you have to add an interpreter with shebang:
Your CandidateCode.m:
#!/usr/bin/octave -q
a = input("");
b = input("");
printf("%d", a+b);
If you want to run it from within Octave, just execute "CandidateCode" (without ./ and .m)

Related

Run Octave function form shell

It is possible to write a function directly in the octave shell?
A=147;
B=26.3;
C=5.4;
d=0.35*A;
function S=function_test(A,B,C,d)
S=2*A*B*C*d;
end
I tried this but if I wanted to know the value of "S", this error appears:
error: 'S' undefined near line 1, column 1
Yes it is possible. You does it correctly. But you missed indicating how you call the function. For me, no error occurs:
≫ function_test(1,2,3,4)
ans = 48
≫ res = function_test(1,2,3,4)
res = 48
≫ S = function_test(-1,3,5,7)
S = -210
≫

Octave error (error: max_recursion_depth exceeded) how to fix it?

I have run the following code in the Octave (Octave-6.2.0 (Local) (GUI)) and the output is shown. I have made an error intentionally, but when I fix it, it does not recognize it. Even when I have copied and pasted the following code which does not have an error it shows the same error message. By the way, it can be solved if I close Octave and open it again.
P=[1200 3000 4200 5500];
I=[10000];
function result = irrm(P,I)
result = 100*irr(P,I)
end
irrm(P,I);
Output:
>> rr
result = 11.798
The code with an error is:
P=[1200 3000 4200 5500];
I=[10000];
function result = irr(P,I)
result = 100*irr(P,I)
end
irrm(P,I);
The output of the code with an error is:
>> rr
error: max_recursion_depth exceeded
error: called from
irr
irr at line 5 column 10
irrm at line 5 column 10
rr at line 7 column 1

Octave puts file read by dlmread to console

myFile.asc is a large point cloud with million of points (rows) in the form of
-13.204000000 30.858300000 15.898300000
-13.204300000 30.864600000 15.899400000
-13.195000000 30.857300000 15.901000000
P = dlmread('/myPath/myFile.asc', " ")
stores the pointcloud successfully in P but unfortunately gives each line to console out in Octave. How can I suppress the logging here?
You can add a semicolon at the end to suppress the output:
P = dlmread('/myPath/myFile.asc', ' ');

octave cannot find fltk XGetUtf8FontAndGlyph symbol

octave 3.8.2 produces this error on loading:
error: /usr/lib64/octave/3.8.2/oct/x86_64-pc-linux-gnu/PKG_ADD: /usr/lib64/octave/3.8.2/oct/x86_64-pc-linux-gnu/__init_fltk__.oct: failed to load: /usr/lib64/fltk/libfltk_gl.so.1.3: undefined symbol: XGetUtf8FontAndGlyph
error: called from:
error: /usr/lib64/octave/3.8.2/oct/x86_64-pc-linux-gnu/PKG_ADD at line 6, column 1
GNU Octave, version 3.8.2
I obtain the following information about configuration of graphics libraries
octave:1> octave_config_info().GRAPHICS_LIBS
ans = -L/usr/lib64/fltk -Wl,-rpath,/usr/lib64/fltk -Wl,-O1 -Wl,--sort-common -Wl,--as-needed -lfltk_gl -lGLU -lGL -lfltk -lXcursor -lXfixes -lXext -ldl -lm -lX11
and although no graphic toolkits are evidently loaded initially,
octave:2> available_graphics_toolkits
ans = {}(1x0)
I can register them subsequently,
octave:3> register_graphics_toolkit("gnuplot")
octave:4> available_graphics_toolkits
ans =
{
[1,1] = gnuplot
}
octave:5> register_graphics_toolkit("fltk")
octave:6> available_graphics_toolkits
ans =
{
[1,1] = fltk
[1,2] = gnuplot
}
but attempting to load fltk produces an error consistent with the initial warning
octave:7> graphics_toolkit("fltk")
error: feval: /usr/lib64/octave/3.8.2/oct/x86_64-pc-linux-gnu/__init_fltk__.oct: failed to load: /usr/lib64/fltk/libfltk_gl.so.1.3: undefined symbol: XGetUtf8FontAndGlyph
error: called from:
error: /usr/share/octave/3.8.2/m/plot/util/graphics_toolkit.m at line 74, column 5
and of course attempting to plot anything also fails,
octave:8> plot(1:10)
error: feval: /usr/lib64/octave/3.8.2/oct/x86_64-pc-linux-gnu/__init_fltk__.oct: failed to load: /usr/lib64/fltk/libfltk_gl.so.1.3: undefined symbol: XGetUtf8FontAndGlyph
error: called from:
error: /usr/share/octave/3.8.2/m/plot/util/graphics_toolkit.m at line 74, column 5
error: failed to load fltk graphics toolkit
error: base_graphics_toolkit::initialize: invalid graphics toolkit
error: /usr/share/octave/3.8.2/m/plot/util/figure.m at line 94, column 9
error: /usr/share/octave/3.8.2/m/plot/util/gcf.m at line 63, column 9
error: /usr/share/octave/3.8.2/m/plot/util/newplot.m at line 113, column 8
error: /usr/share/octave/3.8.2/m/plot/draw/plot.m at line 219, column 9
Both octave and fltk were compiled from source under gentoo:
x11-libs/fltk-1.3.3-r2:1 USE="opengl -cairo -debug -doc -examples -games -pdf -static-libs -threads -xft -xinerama"
sci-mathematics/octave-3.8.2:0/3.8.2 USE="X doc glpk gnuplot gui imagemagick opengl qhull qrupdate readline sparse zlib -curl -fftw -hdf5 -java -jit -postscript -static-libs"
resulting in configure switches of (for the fltk library):
./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --includedir=/usr/include/fltk --libdir=/usr/lib64/fltk --docdir=/usr/share/doc/fltk-1.3.3-r2/html --enable-largefile --enable-shared --enable-xdbe --disable-localjpeg --disable-localpng --disable-localzlib --disable-debug --disable-cairo --enable-gl --disable-threads --disable-xft --disable-xinerama
and (for octave)
./configure --prefix=/usr --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --mandir=/usr/share/man --infodir=/usr/share/info --datadir=/usr/share --sysconfdir=/etc --localstatedir=/var/lib --libdir=/usr/lib64 --disable-silent-rules --disable-dependency-tracking --docdir=/usr/share/doc/octave-3.8.2 --enable-shared --disable-static --localstatedir=/var/state/octave --with-blas=-L/usr/lib64/blas/reference -lblas --with-lapack=-llapack -L/usr/lib64/blas/reference -lblas --enable-docs --disable-java --enable-gui --disable-jit --enable-readline --without-curl --without-fftw3 --without-fftw3f --disable-fftw-threads --with-glpk --without-hdf5 --with-opengl --with-qhull --with-qrupdate --with-arpack --with-umfpack --with-colamd --with-ccolamd --with-cholmod --with-cxsparse --with-x --with-z --with-magick=GraphicsMagick
If I examine libfltk_gl.so.1.3 with nm, I see that the following symbols are exported:
$ nm -D /usr/lib64/fltk/libfltk_gl.so.1.3
U XCreateColormap
U XGetUtf8FontAndGlyph
w _ITM_deregisterTMCloneTable
w _ITM_registerTMCloneTable
w _Jv_RegisterClasses
U _Z10fl_measurePKcRiS1_i
000000000000e170 T _Z10gl_descentv
000000000000e590 T _Z10gl_measurePKcRiS1_
... <snip>
According to nm manual, the U designates that the symbol is global (external) but unknown. My question is whether this unknown symbol status is the origin of the error reported from octave, suggesting that the problem lies with how fltk was compiled, or whether the octave compilation is somehow at fault.
Edit: Solved by enabling Xft support: Please see comments below, and I thank Andy again for his help.
XGetUtf8FontAndGlyph should be in libfltk.so.1.3.
nm -D /usr/lib/x86_64-linux-gnu/libfltk.so.1.3 |grep XGetU
00000000000c2fc0 T XGetUtf8FontAndGlyph
It's very likely that this is a problem with your configure flags for fltk and not GNU Octave. Just try it with the default settings first.
You can test if the UTF8 stuff with OpenGL is okay with the "cube" test. Just digg into the fltk-source dir tests:
cd fltk-1.3.3/test
make cube && ./cube
Does the text in the lower left of the GL window show up?
Had a similar problem. Was getting the following error while trying to run octave (undefined symbol: _ZN18Fl_XFont_On_Demand5valueEv):
bash-4.3$ octave
error: /usr/local/lib/octave/4.0.2/oct/i686-pc-linux-gnu/PKG_ADD: /usr/local/lib/octave/4.0.2/oct/i686-pc-linux-gnu/__init_fltk__.oct: failed to load: /usr/lib/libfltk_gl.so.1.3: undefined symbol: _ZN18Fl_XFont_On_Demand5valueEv
error: called from
/usr/local/lib/octave/4.0.2/oct/i686-pc-linux-gnu/PKG_ADD at line 3 column 1
Command nm -D /usr/lib/libfltk_gl.so.1.3 showed that symbol _ZN18Fl_XFont_On_Demand5valueEv is undefined (with U):
0000a3d4 T _ZN14Fl_Glut_WindowD1Ev
0000a3d4 T _ZN14Fl_Glut_WindowD2Ev
U _ZN18Fl_Font_DescriptorD1Ev
U _ZN18Fl_Graphics_Driver11clip_regionEP8_XRegion
U _ZN18Fl_XFont_On_Demand5valueEv
The solution was to apply a patch file mentioned here to some files inside source directory of FLTK-1.3.3 and then recompile and reinstall FLTK. Now octave works with FLTK without any problem.

How to trace MySql queries using MySql-Proxy?

I just downloaded the mysql-proxy and created this script lua (found in Mysql docs):
function read_query(packet)
if string.byte(packet) == proxy.COM_QUERY then
print("QUERY: " .. string.sub(packet, 2))
end
end
This is the command-line I'm using:
mysql-proxy -P localhost:1234 -b localhost:3306 --proxy-lua-script=profile.lua --plugins=proxy
When I run a simple query (like "select * from table1"), this error is reported: "failed: .\lua-scope.c:241: stat(C:...\profile.lua) failed: No error (0)"
Note: If I run mysql-proxy without lua script, no error occurs.
I need to install something to get mysql-proxy and query tracing working?
My environment is Windows 7 Professional x64.
Sorry the bad english.
The error you're getting is caused by --proxy-lua-script pointing to a file that mysql-proxy can't find. Either you've typed the name in wrong, you've typed the path in wrong, or you are expecting it in your CWD and it's not there. Or actually, looking at the entire error a little more closely, it seems possible that mysql-proxy itself sees the file in CWD itself OK, but one of the underlying modules doesn't like it (possibly because mysql-proxy changes the CWD somehow?)
Try saving profile.lua to the root of your C: drive and trying different versions of the option like so:
--proxy-lua-script=c:\profile.lua
--proxy-lua-script=\profile.lua
--proxy-lua-script=/profile.lua
One of those would probably work
simple query log lua script:
require("mysql.tokenizer")
local fh = io.open("/var/log/mysql/proxy.query.log", "a+")
fh:setvbuf('line',4096)
local the_query = "";
local seqno = 0;
function read_query( packet )
if string.byte(packet) == proxy.COM_QUERY then
seqno = seqno + 1
the_query = (string.gsub(string.gsub(string.sub(packet, 2), "%s%s*", ' '), "^%s*(.-)%s*$", "%1"))
fh:write(string.format("%s %09d %09d : %s (%s) -- %s\n",
os.date('%Y-%m-%d %H:%M:%S'),
proxy.connection.server.thread_id,
seqno,
proxy.connection.client.username,
proxy.connection.client.default_db,
the_query))
fh:flush()
return proxy.PROXY_SEND_QUERY
else
query = ""
end
end