Dear all,

I am running a simulation program that should write some output to an output file. In fact, if I run my program with the number of iterations equal to 5,000 the program works fine. However, if I run it with 10,000 iterations, an empty output file is created. There is no error message saying that there is overload or lack of memory or something and my command window indicates in the usual way that the program finished running. Does anybody know what the problem could be?

Thanks in advance and regards,
Marjolein

Please show us how you are writing to the file. Did you use ofstream or fstream to open the file for editing? What kind of data are you wtiting in it?
Post some code, please.

Regards,
Luci

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"A person who never made a mistake never tried anything new."
Einstein

I just used cout << in the program and then typed the following in my command window to read from an input file and write to an output file:

repeated_simulation_extended_eff < input_het_n4_a05.txt > output_het_n4_a05_ex_eff.txt

There should not be anything wrong with the code itself, since it works fine for 5,000 iterations. So I just wondered whether somebody recognized the situation...

Nope, not a clue, since we have no code to go on. Maybe you don't have enough memory to run the program ("lack of memory or something").

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Does that happen more often? Because usually I get the message "Abnormal program termination" in these cases...

We'd really like to help you but you really need to stop asking questions and answer those that were asked of you. We have absolutely no idea what we're dealing with so we cannot give you an answer. Read the responses you've already received and respond to the requests. Once we know what you are trying to do, we can help you fix the problem.

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Got a cough? Go home tonight and eat a whole box of Ex-Lax. Tomorrow, you'll be afraid to cough.
-- Pearl Williams

I was asking just one question: whether anybody happens to recognize the situation that in some cases a program does not give any output without returning any error message. Since nobody seems to do so, I tried to avoid the problem by decreasing the number of iterations in part of the program and this worked out well. So my question is not very urgent anymore and I do not need to bother you with (very many) pages of code...
Thanks anyway for your reactions!

The answer to your question is: Yes, it is possible for a program with a bug to terminate abnormally without any error messages. Sometimes the bug could cause problems with large numbers of iterations but would perform as advertised when the same program is run with fewer iterations. Since my programs rarely have bugs (a little joke, folks), I don't know if it happens often.

I am always interested in cases like this, since, if there is some abnormal behavior under certain conditions and not under other conditions, there is either a bug or some program limitation that I would like to know about.

Sweeping bugs under the rug (wow, what a metaphor) is not acceptable if the program is going to be used at some later time. If you only need output now, and you think your output is OK, it's your prerogative to ignore the bug.

Only my opinion, of course.

Regards,
Dave

Thanks! I will check my program and output rigorously to find out whether it is a bug...