On most instances of MATLAB I've used, whenever I had a bug in my code the error message in the command window would show the line number.
However on the computer I am currently using, it shows me only the following:
??? Subscripted assignment dimension mismatch.
Is there anyway to get the line number to show again instead of ?????
What you are doing is using Run Section or Run and Advance as #canzar said. If you run scripts like this there is no 'line number', just as when you copy-paste code and run it in the command-window will not show you the line number on the error.
If you run the script using run or by pressing F5 it does know the line number and then prints that on the error statement. Good to know for debugging is to go to the tab editor->breakpoints->dbstop on error. If you press that it will keep your variables as present when the memory occurs, as opposed to throwing everything out when debugging functions.
Related
I am very new to Selenium and Eclipse.
I have a question (actually 2 questions) about debugging.
When I am debugging in Eclipse (Version: 2021-06 (4.20.0)), so I do not get visibility of all variables I have defined in the method.
For example, (see the screen shot attached) I have added string variable testSigned and assigned a value to it. Actually the purpose is to verify the text value contained in web element table_AdditionalDocumentation.
I defined Toggle Line breakpoint at line 395.
I started to execute in debug mode, got to the line 395.
However, I do not see the value of testSigned in Variables tab.
I noticed it does show values only of the variable which would be returned by the method, correct me if I am wrong.
Please, tell me how to get those values I have defined visible.
2.Additionally, please, let me know which button to press if for example after line 395 I want not to go line by line (F6), but just to run the code to the end.
For the first question, I'm not certain, but it might be because you haven't initialized that variable with a value. Try setting it to an empty string on the declaration line.
For the second question, if you set a breakpoint on the line you want to get to, just Resume (F8), and it will stop at the next breakpoint it hits, hopefully the one at the end of your method. Alternatively, if you just want to stop at the line right after the method returns (which will show the return value), you can click "Step Out" (F7) for that.
I'm not entirely sure how, but my copy of MATLAB R2013b has stopped showing which line my errors occur at.
I'll just get errors like:
Subscripted assignment dimension mismatch.
But no line number to go along with it, so I have no idea which part of my code is causing the problem!
Did I mess up a setting somewhere?
Enable line numbering in the editor with Preferences -> Editor/Debugger -> Display -> Show line numbers
When running code segments (for example, using Ctrl+Enter with the Windows default key bindings), line numbers will not be displayed. You can see the line on which the error is caused by directly running the script or calling the function in which it occurs.
I'm not entirely sure how, but my copy of MATLAB R2013b has stopped showing which line my errors occur at.
I'll just get errors like:
Subscripted assignment dimension mismatch.
But no line number to go along with it, so I have no idea which part of my code is causing the problem!
Did I mess up a setting somewhere?
Enable line numbering in the editor with Preferences -> Editor/Debugger -> Display -> Show line numbers
When running code segments (for example, using Ctrl+Enter with the Windows default key bindings), line numbers will not be displayed. You can see the line on which the error is caused by directly running the script or calling the function in which it occurs.
I wonder what the difference is between entering a few lines in the command window, or letting a script execute them.
In the question Escape from nested try - catch statement I have an example function. I have put the selected code in a script and called it, however then it does not work properly. On the other hand, when I
select the lines and hit f9, it works as expected.
The lines are:
dbclear all
dbquit
dbstop if caught error
I call the example function as such:
dbstop if caught error
mytestmain
And the example function is:
function mytestmain
try
mytestsub
catch
end
% Definition of subfunction, may or may not be in the same .m file
function mytestsub
try
a=b; %Intentionally generate an error as b is not defined
catch
end
I think it's related to MATLAB's just-in-time (JIT) compiler, which compiles functions before it runs them.
It seems that it compiles functions differently if dbstop is set or not (see here for reference). As it currently stands, MATLAB can not recompile a function while it is run (just try saving a changed function during a dbstop, and you will get a message informing you). As you can add and remove breakpoints during a dbstop I think you can also do so programmatically, but it should be impossible to "turn on" debugging if it wasn't turned on at "compile time"
So in your cases:
Using F9 it's just pasted and parsed as if you input it manually. So first dbstop is set, then mytestmain gets compiled and executed.
Running as a script will first compile the script and mytestmain and then execute it - so dbstop would be set after compilation and therefore not in effect.
Depending on what you mean by "doesn't work", it could just be because the debugger is a special context and certain debugger commands - dbup, dbdown, and dbquit - only work when you're at a debugger "K>>" prompt. Once you call a script, you're no longer at the debugger prompt but in normal code execution - inside a nested M-code call stack - and they just don't work there. When you F9, it does the lines individually, so each one is done from the prompt.
As a workaround, if you really want to execute a sequence of debugger commands like this, you could write a little Java Swing widget to enter the text in to the command window just as though you were typing it in.
I am newbie to MATLAB .I have written a code to upsample a data.when executed always shrows the particular error(below)
??? Input argument "n" is undefined.
Error in ==> upsamp at 7
mm=min(n)
but when i just write the foll. output [n1,y]=upsamp([1,2,3,4,5,6],-1:4,3) command window ,its shows me the correct upsampled data with its figure.
then why the error is popping up? Or i just click on run button,and error is shown in command window.
Please help me out to debug that error:
My code is
function[n1,y]=upsamp(n,x,I)
mm=min(n)
mx=max(n)
n1=mm*I:(mx*I+I-1)
x1=x'
x1=[x1,zeros(length(x),I-1)]
x1=x1'
y=(x1(:))'
subplot(2,1,1)
stem(n,x)
title('original sequence ')
xlabel('Range')
ylabel('sequence')
subplot(2,1,2)
stem(n1,y)
title(' unsampling')
xlabel('Range')
ylabel('sequence')
end
As others have noted, if you want to run a function that takes input arguments, you have to call it manually from the command prompt with any required arguments.
Otherwise, if you like to use the Run button (F5) from the editor, consider creating a run configuration (they can be used in smart ways)
The "run" button is only for scripts (i.e. just a plain list of statements without "function" at the top). This is a function, so it should only get called from the matlab command line like you described.
The run button calls your function with no arguments.
Since arguments to your function are non-optional, you get an error.
Either call your function from the interactive Command Window, or write a short script that provides appropriate arguments, and use the Run button with that script. You can still single-step into your function.