I have the following call to a function:
callfun(I1, I2, [X Y ones(n,1)], w, m)
But, I'm getting:
Error: File: callfun.m Line: 20 Column: 3
Unexpected MATLAB expression.
Why is that?
Thanks.
The error says, that your function callfun has a syntax error in line 20. Probably some character which is not allowed.
It can be also a problem of duplicated function definition. A function inside callfun.m may have the same name as a built-in MATLAB function, what yields an error.
From http://www.mathworks.com/matlabcentral/answers/214993-how-to-solve-error-unexpected-matlab-expression-workspacefunc-287:
Do you have any user-defined functions called builtin, strjoin, or strsplit? MATLAB has these defined internally, and having any outside functions that shadow these built-in ones would result in this error. If you are unsure if you have created such functions, typing the command:
>>which functionName -all
will show you the path to all items on the MATLAB path with the name "functionName"
Related
I am using Octave. I wrote this simple script with name example1.m:
t = [0:0.01:5];
x2 = exp(-3*t);
plot(t,x2);
I am waiting for the plot, but I get this error:
Octave: invalid use of script in index expression in exp function
This script works with other default functions like abs, log, etc. and it worked in the past with the exp function. But now it's not.
What is the problem?
I can execute Maxima code from Octave like this and it works:
mm=maxima("diff(a*x^3-b*x^2+x+d,x,1)")
but how can I execute multi line commands?
Example code below that works in Maxima
kill(all)$
numer:true$
ratprint:false$
angle_in_bits:3779$
total_fs:18136$
s:solve(angle_deg=(angle_in_bits/total_fs*360),angle_deg)$
round(s);
[round(angle_deg)=75]
When I try the code below in Octave I get syntax errors
mm=maxima("kill(all)$
numer:true$
ratprint:false$
angle_in_bits:3779$
total_fs:18136$
s:solve(angle_deg=(angle_in_bits/total_fs*360),angle_deg)$
round(s);")
Errors that I get:
>>> mm=maxima("kill(all)$
numer:true$
ratprint:false$
angle_in_bits:3779$
total_fs:18136$
s:solve(angle_deg=(angle_in_bits/total_fs*360),angle_deg)$
round(s);")
error: unterminated character string constant
parse error:
syntax error
>>> mm=maxima("kill(all)$
^
>>> _ide_reload_variables_list( whos() );
error: 'numer' undefined near line 1 column 1
error: invalid base value in colon expression
error: 'ratprint' undefined near line 1 column 1
error: invalid base value in colon expression
parse error:
syntax error
>>> angle_in_bits:3779$
^
parse error:
syntax error
>>> total_fs:18136$
^
parse error:
syntax error
>>> s:solve(angle_deg=(angle_in_bits/total_fs*360),angle_deg)$
^
error: unterminated character string constant
parse error:
syntax error
>>> round(s);")
^
Thanks to Fred Senese and rayryeng for the assist.
I know someone may need this so here's some example code. This bit of code allows you to directly access maxima's symbolic solver from octave (allows you to execute multiple lines of maxima's commands). Since octave doesn't have a good symbolic solver yet this will come in handy for another person down the line.
mm=maxima("(kill(all), numer:true, ratprint:false, angle_in_bits:3779, total_fs:18136, s:solve(angle_deg=(angle_in_bits/total_fs*360),angle_deg),(s))")
%mm = '[angle_deg = 75.01323334803705]';
[si ei xt mt] = regexp(mm, '(\d)*(\.)?(\d)*');
number = str2num(mt{1})
>>>number = 75.013
I will suppose here that you are using QtOctave which I am guessing from googling your error message "_ide_reload_variables_list( whos() );"
If this is not so, none of the following may apply to your question.
typing help maxima at the prompt points me to a file /usr/share/qtoctave/scripts_octave/maxima.m
with this contents:
function result=maxima(command)
in="";
in=sprintf("echo \"string(%s);\"|maxima --very-quiet", command);
[status,result]=system(in);
%if(status!=0) result=""; endif;
result = deblank ( strjust ( strrep (result, "%", "") ,"left") );
endfunction
Which tells me that maxima is called via octave's function system in a very special way that is not allowing for multiple commands in maxima.
modifying the assignment of in in the way below would allow you to call the function maxima now with a cell array of commands maxima({command_1,command_2}) where command_i are strings.
in=['echo ', sprintf('\"%s;\" ',command{:}), '| maxima --very-quiet'];
Please note that the function system still returns only one output, the one that is sent to standard out by maxima.
This may also be of interest for you as it describes methods of octave's interaction with subprocesses.
I am not sure if this helping much as I think the modification provided by me is only of very superficial use, but maybe it helps you to understand better what octave is doing if you tell it maxima(something). It helped me.
Last but not least as far as I know there is no real interface between octave (or matlab) and maxima. I hope someone will correct me if I am wrong about that.
I have Octave and Maxima in my Linux laptop (Ubuntu). There exist system -function in Octave, which could be used to run terminal -commands.
In terminal it is possible to call maxima functions by using pipe
(add quit(); to the end of maxima command) :
$ echo "factor(12345); quit();" | maxima
Maxima 5.41.0 http://maxima.sourceforge.net
using Lisp GNU Common Lisp (GCL) GCL 2.6.12
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) (%o1) 3 5 823
$
In Octave' system -commad use double "" inside "-marks to get " :
[status,output]=system("echo ""factor(565);quit();""|maxima")
status = 0
output =
Maxima 5.41.0 http://maxima.sourceforge.net
using Lisp GNU Common Lisp (GCL) GCL 2.6.12
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.
(%i1) (%o1) 5 113
Extra txt could be cutted out from the output -string in Octave. Use Maxima's properties to run it's commands from a script file, and the script could be created in Octave.
Br. Juha (juhap.karjalainen#mail.suomi.net)
I'm new to MATLAB, and I have the following problem:
I have the line:
[~, j] = min(matrix);
I don't understand what the ~ sign is for(I have to learn this code..) and the error is:
Expression or statement is incorrect--possibly unbalanced (, {, or [.
What can be the reason?
Another question, suppose I have got a file.m and inside of it I have the declaration:
methods (Static)
function var = func(n, d)
How do I call this function with the 2 parameters from the command windows?
i dont understand whats for ~ sign
Discard first returning output, it is not going to be used.
What can be the reason?
What version of Matlab do you use? This syntax has only been part of MATLAB since about R2009b or so.
How do i call this function func with the 2 parameters from the command windows?
Yes, otherwise - http://www.mathworks.com/help/matlab/matlab_prog/support-variable-number-of-inputs.html
I have a Matlab file with multiple functions defined. When calling the file, I get the following error: "Error: File: kmeans.m Line: 20 Column: 1\n Function definition is misplaced or improperly nested."
How can I get rid of the error?
Make sure every function has a matching end.
I wrote the following function in a file named conditionals.m:
function result = conditionals(category, feature)
result=5;
end
I call this function from Octave's command line:
v=conditionals(3,4)
I get the following error:
error : A(I) : Index exceeds matrix dimension.
Whats wrong here?
The error:
error : A(I) : Index exceeds matrix dimension.
Indicates that octave thinks that conditionals is a matrix, not a function.
Octave probably doesn't know that conditionals is a function - and instead it's treating it as a matrix.
Have you checked to see if the function is in Octave's search path?
This works for me.
octave> function result = conditionals (category, feature)
> result = 5;
> endfunction
octave> v = conditionals (3, 4)
v = 5
The error suggests that you have a variable with the same name as the function. Type whos at the Octave prompt to see a list of defined variables. If you see one named conditionals, remove it with clear conditionals
Also, if conditionals is a conditionals.m file, make sure it's on the function search path. Run path at the Octave prompt to see the function search path. Run which conditionals at the command prompt to see where the function is located.
It happened to me as well and it can happen on any command, regardless of the command name. When I run the PS1(">>"); to change the command prompt in Ovtave, I got the same error.
octave-3.2.3.exe:9> PS1(">>");
error: A(I): Index exceeds matrix dimension.
As others also mentioned, this error fires when there is a parameter with the same command name. It happens when we mistakenly enter the command with wrong syntax and hence, octave run the command and produce a variable with your command name that overload the internal command.
You can verify this status by who command. If you can see the same variable name as your command here, you have to remove it. Use clear variable_name to remove the variable.
Here is my output for PS1 command.
Hope it helps.