Why does it take MATLAB so long to print hello world?

Question

Matthew Elmer 2023-9-6

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编辑： Jon 2023-9-15

I apologize in advance for the formatting -- this forum post editor does not conform to the CommonMark standard, and thus I cannot properly share non-MATLAB code snippets. A distinct font will have to do until MathWorks adds support for basic Markdown features. EDIT: Somebody ninja-edited my question to get rid of the distinct font. No font will have to do, now. Seriously -- how do you guys discuss anything involving terminal use in this forum???

It takes MATLAB ~2.6 seconds to print "Hello, World!" from the command line:

$ time matlab -nojvm -noFigureWindows -nodisplay -batch "disp('Hello, World!')" Hello, World!

real 0m2.601s

user 0m2.645s

sys 0m0.267s

For comparison, that's 90x longer than the time it takes to read from stdin, compile, run, delete, and echo to stdout the equivalent C program:

$ time echo $(gcc -xc - <<< '#include "stdio.h"

int main() { printf("Hello, World!\n"); return 0; } ' && ./a.out && rm a.out) Hello, World!

real 0m0.029s

user 0m0.025s

sys 0m0.004s

It's also 170x longer than it takes to perform the Python equivalent:

$ time python3 -c "print('Hello, World!')"

Hello, World!

real 0m0.015s

user 0m0.012s

sys 0m0.004s

Why does MATLAB seem to take hundreds of times longer than it needs to in order to run a simple "Hello, World!" application?

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Walter Roberson 2023-9-11

To insert non-MATLAB code in postings, as code for people to be able to use the Copy button to copy the code to execute on their own machines:

Click on the editor '>' toolbar button, in the 'CODE' section of the toolbar. Paste the code in to the region the editor created. If the editor automatically indented the code and you do not want the automatically formatted version, then after the paste, press control-Z : that will undo the automatic formatting.

To insert anything in postings as a mix of code and output for people to look at, without the expectation that they will want to copy it for execution on their own machines:

Click on the rightmost icon in the toolbar 'INSERT' section -- the one that looks like a stack of 4 lines. Paste the code/output in to the region the editor created. If it automatically formatted in a way you do not like, then press control-Z to undo the formatting.

Note: if you have already entered code into the editor as regular text, then you can highlight the code with your mouse, and then click on the '>' button and the text will be converted to a code region; you might need to control-Z to undo formatting.

Matthew Elmer 2023-9-15

@Walter Roberson Please post an example that includes correctly-syntax-highlighted Python, along with an example that contains simple monospace text without paragraph spacing between newlines.

Jon 2023-9-15

编辑：Jon 2023-9-15

@Matthew Elmer While I understand that you would like to be able to more easily post nicely formatted code in other languages, I think the currently implemented "Code" button is mainly intended for people to post MATLAB code as this is the focus of MATLAB answers.

I haven't really seen too many instances where people have had questions where it was important to them to post nicely formatted code in other computer languages. So if this is short coming of the MATLAB Answers site, I don't think it affects that many users.

I find sites like Stack Overflow are more oriented to general programming issues and go there for non MATLAB specific questions.

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Answer 1

Image Analyst 2023-9-6

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What MATLAB commands did you issue from the command line? What you gave does not work:

>> $ time matlab -nojvm -noFigureWindows -nodisplay -batch "disp('Hello, World!')"

$ time matlab -nojvm -noFigureWindows -nodisplay -batch "disp('Hello, World!')"

↑

Error: Invalid text character. Check for unsupported symbol, invisible character, or pasting of non-ASCII

characters.

>> time matlab -nojvm -noFigureWindows -nodisplay -batch "disp('Hello, World!')"

Incorrect number or types of inputs or outputs for function 'time'.

Was it from a console window prompt instead of the command prompt in MATLAB? If it was, it looks like you may be launching the full MATLAB program, just with no user interface shown, which of course will take more time than if MATLAB is already up and running. You will of course have lots of overhead in that case. Maybe you should test out some longer snippet of code that takes much longer to compute so the overhead is not a significant part of the total time. When I do it in MATLAB I get this on my old, slow computer:

Hello, World!

Elapsed time is 0.000162 seconds.

>>

To format your code as code, you highlight the code with the mouse and then click the Code icon on the Answers edit box tool ribbon. Pretty simple.

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Matthew Elmer 2023-9-7

编辑：Matthew Elmer 2023-9-7

@Image Analyst is essentially saying that only throughput ever matters and that you can forget about latency in all cases, for all programs, for all problem domains, every time. I don't even have to address such a ridiculous claim, because you can already guess what the response might be.

People like @Image Analyst are why it takes 30 seconds to spool up Microsoft Word, MATLAB, Discord and other Electron apps, etc. I'm sick of modern software being 100x - 1000x slower than it needs to be and having mile-long excuse trains that keep it that way.

If there's a problem with how long it takes to launch the program, maybe fix it? Clearly Python wastes no time at all in starting its interpreter.

Hilariously, @Image Analyst had to go digging for some article that someone else (likely ChatGPT) wrote about an entirely unrelated performance comparison to have any sort of point to bring to the discussion. Unfortunately, I'm not trying to do a matrix multiplication here. I'm just trying to start MATLAB in a reasonable timeframe. And by the way, that article is embarrasing. It doesn't even cite the benchmark that supposedly reveals how blazingly fast MATLAB is! It also naively touts the power of MATLAB's multithreading "capabilities," despite the fact that MATLAB's parallel "toolbox" is widely recognized to be near worthless on anything with more than 3 CPU cores. This part of the article got a chuckle from me:

"MATLAB uses highly optimized libraries like Intel’s Math Kernel Library (MKL) and BLAS (Basic Linear Algebra Subprograms) for its matrix operations. These libraries are written in low-level languages like C and Fortran, which are known for their speed and efficiency.

NumPy also uses BLAS and LAPACK (Linear Algebra Package) for matrix operations..."

I'm not sure what point they're trying to make here, but they didn't do so well, lol.

@Image Analyst still has not shown me how to post non-MATLAB code snippets, by the way, even though he claims it's "Pretty simple."

Matthew Elmer 2023-9-9

My apologies if my tone came across as angry. I really would like to come across as friendly, but I cannot compromise on calling people out on responses that are actively counterproductive to users with time/resource constraints and the computer programming industry at large. The benchmarks that I shared show that MATLAB could be a lot faster on headless startup and thus a lot more valuable to more users. If I have to contend with an avalanche of excuses, especially ones like this that don't match the friendly tone you're requesting either, I'm going to have to compromise on tone a bit for the sake of clarity.

Your criticism is well taken, though, and I'll try even harder to keep the atmosphere polite.

Jon 2023-9-11

Thanks Matthew, I very much appreciated your thoughtful response regarding keeping it friendly.

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Answer 2

Jon 2023-9-6

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编辑：Jon 2023-9-6

在 MATLAB Online 中打开

I'm not sure how you are running your test, running this script inside this online environment seems to indicate it is very fast compared to what you report

tic
disp('Hello World!')
Hello World!
toc
Elapsed time is 0.015690 seconds.

When I just type on the command line on my laptop, it is even faster

tic,disp('Hello World'),toc

Hello World

Elapsed time is 0.000805 seconds.

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Matthew Elmer 2023-9-6

My timing was done in a Bash terminal. Try running the Python command or compiling a C program and you'll see that it's not the same as MATLAB's REPL.

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Answer 3

John D'Errico 2023-9-6

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To me, this all seems to be making a mountain out of a mole hill.

Yes, if you are going to launch MATLAB, even with no gui interface, MATLAB will surely cache all the functions it uses. It will do lots of crapola that you don't care about, IF your only goal is to display a line of text, and then quit. If that is what you will do on your computer, then you need ot be using a different tool, not MATLAB. That Python (or C) is faster to display a line of text, good for Python. Use it instead.

In your case, it appears that you want to use MATLAB as you are trying to use it, AND that the overhead of booting MATLAB every time is high. If you compare any of those anguages, they all have their advantages, and disadvantages. As @Image Analyst points out, for at least some operations MATLAB is faster than Python. (I can also point out one specific case that I know of where Python wins the battle by a mile. But I also have a workaround in MATLAB.)

I'm sorry, but no language is perfect. They all live under their own sets of fundamental assumptions that influence what they will do well.

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Matthew Elmer 2023-9-7

It's not my choice to use MATLAB. I'm merely accomodating those who don't have the time to learn something better. After seeing how much time they spend sitting around, no wonder they don't have any left for learning a better language!

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