Can I give "static" input on VSCode? - visual-studio-code

My college has a proprietary IDE for C programming. It is very simple: Half the screen for the code, and the other half has the input and output (as you can see here).
The input works in a way you only have to type it once, and the program will read each line on every scanf there is. I find this a convenient way of testing, instead of giving the input every time I compile the program, and I'm wondering if there's any way to do something similar on VSCode.

Related

What is a "base" program on a Casio calculator?

When I make a program, I have the option to make it either "run" or "base".
https://src.mrhitech.repl.co/calcmanual.pdf (backup; the original one seems to have been taken down) mentions a "base" program several times on pages 213-214, but never says what it entails (other than having a big "B" next to the filename).
Whatever I do to the program, it seems completely indistinguishable from a "run" program–a program that runs when you select it and hit F1 or EXE.
I'm using a CASIO fx-9860GII if that matters.
EDIT: NEW INFO:
It seems that a "base" calculator program has different commands available than a "run" program–when you edit the program you are much more restricted–you can't use if, while, or for loops, as well as advanced calculator tools–but you also have the ability to convert numbers between different bases.
That still doesn't answer what you are supposed to use it for, but I hope it helps people answer.

Can the MATLAB editor show the file from which text is displayed? [duplicate]

In MATLAB, how do you tell where in the code a variable is getting output?
I have about 10K lines of MATLAB code with about 4 people working on it. Somewhere, someone has dumped a variable in a MATLAB script in the typical way:
foo
Unfortunately, I do not know what variable is getting output. And the output is cluttering out other more important outputs.
Any ideas?
p.s. Anyone ever try overwriting Standard.out? Since MATLAB and Java integration is so tight, would that work? A trick I've used in Java when faced with this problem is to replace Standard.out with my own version.
Ooh, I hate this too. I wish Matlab had a "dbstop if display" to stop on exactly this.
The mlint traversal from weiyin is a good idea. Mlint can't see dynamic code, though, such as arguments to eval() or string-valued figure handle callbacks. I've run in to output like this in callbacks like this, where update_table() returns something in some conditions.
uicontrol('Style','pushbutton', 'Callback','update_table')
You can "duck-punch" a method in to built-in types to give you a hook for dbstop. In a directory on your Matlab path, create a new directory named "#double", and make a #double/display.m file like this.
function display(varargin)
builtin('display', varargin{:});
Then you can do
dbstop in double/display at 2
and run your code. Now you'll be dropped in to the debugger whenever display is implicitly called by the omitted semicolon, including from dynamic code. Doing it for #double seems to cover char and cells as well. If it's a different type being displayed, you may have to experiment.
You could probably override the built-in disp() the same way. I think this would be analagous to a custom replacement for Java's System.out stream.
Needless to say, adding methods to built-in types is nonstandard, unsupported, very error-prone, and something to be very wary of outside a debugging session.
This is a typical pattern that mLint will help you find:
So, look on the right hand side of the editor for the orange lines. This will help you find not only this optimization, but many, many more. Notice also that your variable name is highlighted.
If you have a line such as:
foo = 2
and there is no ";" on the end, then the output will be dumped to the screen with the variable name appearing first:
foo =
2
In this case, you should search the file for the string "foo =" and find the line missing a ";".
If you are seeing output with no variable name appearing, then the output is probably being dumped to the screen using either the DISP or FPRINTF function. Searching the file for "disp" or "fprintf" should help you find where the data is being displayed.
If you are seeing output with the variable name "ans" appearing, this is a case when a computation is being done, not being put in a variable, and is missing a ';' at the end of the line, such as:
size(foo)
In general, this is a bad practice for displaying what's going on in the code, since (as you have found out) it can be hard to find where these have been placed in a large piece of code. In this case, the easiest way to find the offending line is to use MLINT, as other answers have suggested.
I like the idea of "dbstop if display", however this is not a dbstop option that i know of.
If all else fails, there is still hope. Mlint is a good idea, but if there are many thousands of lines and many functions, then you may never find the offender. Worse, if this code has been sloppily written, there will be zillions of mlint flags that appear. How will you narrow it down?
A solution is to display your way there. I would overload the display function. Only temporarily, but this will work. If the output is being dumped to the command line as
ans =
stuff
or as
foo =
stuff
Then it has been written out with display. If it is coming out as just
stuff
then disp is the culprit. Why does it matter? Overload the offender. Create a new directory in some directory that is on top of your MATLAB search path, called #double (assuming that the output is a double variable. If it is character, then you will need an #char directory.) Do NOT put the #double directory itself on the MATLAB search path, just put it in some directory that is on your path.
Inside this directory, put a new m-file called disp.m or display.m, depending upon your determination of what has done the command line output. The contents of the m-file will be a call to the function builtin, which will allow you to then call the builtin version of disp or display on the input.
Now, set a debugging point inside the new function. Every time output is generated to the screen, this function will be called. If there are multiple events, you may need to use the debugger to allow processing to proceed until the offender has been trapped. Eventually, this process will trap the offensive line. Remember, you are in the debugger! Use the debugger to determine which function called disp, and where. You can step out of disp or display, or just look at the contents of dbstack to see what has happened.
When all is done and the problem repaired, delete this extra directory, and the disp/display function you put in it.
You could run mlint as a function and interpret the results.
>> I = mlint('filename','-struct');
>> isErrorMessage = arrayfun(#(S)strcmp(S.message,...
'Terminate statement with semicolon to suppress output (in functions).'),I);
>>I(isErrorMessage ).line
This will only find missing semicolons in that single file. So this would have to be run on a list of files (functions) that are called from some main function.
If you wanted to find calls to disp() or fprintf() you would need to read in the text of the file and use regular expresions to find the calls.
Note: If you are using a script instead of a function you will need to change the above message to read: 'Terminate statement with semicolon to suppress output (in scripts).'
Andrew Janke's overloading is a very useful tip
the only other thing is instead of using dbstop I find the following works better, for the simple reason that putting a stop in display.m will cause execution to pause, every time display.m is called, even if nothing is written.
This way, the stop will only be triggered when display is called to write a non null string, and you won't have to step through a potentially very large number of useless display calls
function display(varargin)
builtin('display', varargin{:});
if isempty(varargin{1})==0
keyboard
end
A foolproof way of locating such things is to iteratively step through the code in the debugger observing the output. This would proceed as follows:
Add a break point at the first line of the highest level script/function which produces the undesired output. Run the function/script.
step over the lines (not stepping in) until you see the undesired output.
When you find the line/function which produces the output, either fix it, if it's in this file, or open the subfunction/script which is producing the output. Remove the break point from the higher level function, and put a break point in the first line of the lower-level function. Repeat from step 1 until the line producing the output is located.
Although a pain, you will find the line relatively quickly this way unless you have huge functions/scripts, which is bad practice anyway. If the scripts are like this you could use a sort of partitioning approach to locate the line in the function in a similar manner. This would involve putting a break point at the start, then one half way though and noting which half of the function produces the output, then halving again and so on until the line is located.
I had this problem with much smaller code and it's a bugger, so even though the OP found their solution, I'll post a small cheat I learned.
1) In the Matlab command prompt, turn on 'more'.
more on
2) Resize the prompt-y/terminal-y part of the window to a mere line of text in height.
3) Run the code. It will stop wherever it needed to print, as there isn't the space to print it ( more is blocking on a [space] or [down] press ).
4) Press [ctrl]-[C] to kill your program at the spot where it couldn't print.
5) Return your prompt-y area to normal size. Starting at the top of trace, click on the clickable bits in the red text. These are your potential culprits. (Of course, you may need to have pressed [down], etc, to pass parts where the code was actually intended to print things.)
You'll need to traverse all your m-files (probably using a recursive function, or unix('find -type f -iname *.m') ). Call mlint on each filename:
r = mlint(filename);
r will be a (possibly empty) structure with a message field. Look for the message that starts with "Terminate statement with semicolon to suppress output".

Prolog read input without full stop

I am currently programming a small text-based adventure game in SWI-Prolog. Hence, the user will have to give commands like "goto(room)" or "goto room".
However the problem is that you always have to finish the command with a full stop, i.e.
"goto(room)." instead of "goto(room). This is not very user-friendly.
I have a predicate that reads a command and then executes the input. How can I automatically add the full stop if there is none (if there already is one the input should just be executed)?
Thanks in advance!
Regards,
Volker
Obviously you are using read/1 or some variation; this is supposed to be used to read valid prolog terms (and that's why you need a full-stop).
The solution would be to parse the input on your own (check primitive char io, read utilities and io in general (you will probably need just the read utilities though)) and then convert it to a term.
Additionally, you can create a small natural language with DCGs and use; for example the user could just write goto room instead of goto(room).
On the other hand, I personally don't think that having to skip a full-stop it will be a lot more user friendly if they have to type prolog terms anyway.

Tips on optimizing this code that loads multiple files in Matlab?

fname = dir('*sir');
dayH = zeros(length(fname),1360,3600);
for i=1:length(fname)
dayH(i,:,:) = loadsir(fname(i).name);
end
fname = dir('*sir');
dayH = cell(1,length(fname));
for i=1:2
dayH{i} = loadsir(fname(i).name);
end
Basically it loads all my files. I have a separate .m file called loadsir that loads those specialized files. The output of the .sir files will be an array 1360x3600.
Right now that code is crashing saying, "Cannot display summaries of variables with more than 524288 elements." I guess it's because 1360X3600 = 5,000,000 about?
Putting Serg's comment as an answer:
Most likely you missed a semicolon (;) somewhere in loadsir. Matlab then thinks you want to print the output, which it won't do due to the large number of elements.
Additionally, to prevent such things from happening in the future:
Matlab is an interpreted language, meaning, no compilation is necessary. Any and all code can be parsed while you type it, which allows for things like auto-correct. Of course, this sort of thing is included already in standard Matlab. If you don't already, code in Matlab's own editor every now and then. It warns you of such silly mistakes/errors (and a lot more), including but not limited to, via the right vertical bar in the editor. The little square at the top right of the window should always be green. If it's orange or red, there's things to be improved or corrected, respectively.
The right vertical bar is an overview of all the lines in your file that leave room for improvement. If a small orange/red bar appears somewhere, a mouseover will tell you what's wrong with what line. Clicking it will navigate the editor to the line, which will likely be wavy-underlined in either orange or red. Mouse-over the line often gives useful suggestions, and <alt>+<enter> is often enough to fix the simple mistakes. I find it an indispensable tool when developing larger applications in Matlab.
You can of course configure which errors/warnings this tool ("code analyzer", formerly "mlint") displays. Sometimes, there will be a warning about an inefficiency that you simply cannot work around. Add an OK-directive behind the line to suppress it (%#ok), but don't make a habit of suppressing anything and everything "annoying" because that will of course completely beat the purpose of the code analyzer :)

Evaluating the performance in time of a specific portion of the matlab code?

I want to be able to measure performance of my code and find the lacking parts. What is the proper way to do that in Matlab? I know I can use just tic: and toc; functions to see the time passing but there might be more convenient way.
The most convenient way is to use the GUI profiler tool. You can find it in the dropdown menus (Desktop->Profiler), or you can start it from the command line by typing profile viewer. Then you enter the name of the function at the top of the window, hit "run", and wait till the code is done running. Clicking on the links brings you into the respective function, where you can see runtime line-by-line.
Note that timing code that runs very fast and for only a handful of iterations can be tricky; for these cases you may want to use the timeit function from the Matlab File Exchange.
The profile tool reports time spent on each function and in each line of code in the program.
It takes longer to implement so if you are analyzing a short piece of code, tic-toc will do the job better.