Unexpected exception

[zohannn]

Hi I have a weird problem.
I have the attached nl file I want to read.
I successfully run the nl-exampl.cc but when I run the following code in my own library:

        std::string filename = std::string("FinalPosture.nl");
        DimensionPrinter printer;
        try
        {
              mp::ReadNLFile(filename, printer);
        }
        catch (const std::exception &exc)
        {

            std::cerr << exc.what();
        }     

I get the following exception:
FinalPosture.nl:22677:5: expected double.

Please what does it mean? How can I solve the problem?
Thank you.

FinalPosture.nl.zip

[vitaut]

Thanks for the bug report. Unfortunately I cannot reproduce it, compiling and running

#include "mp/nl.h"
#include <iostream>

struct DimensionPrinter : mp::NLHandler<int> {
  void OnHeader(const mp::NLHeader &h) {
    fmt::print("Variables:   {}\n", h.num_vars);
    fmt::print("Constraints: {}\n", h.num_algebraic_cons);
    fmt::print("Nonzeros:    {}\n", h.num_con_nonzeros);
  }
};

int main() {
  std::string filename = std::string("FinalPosture.nl");
  DimensionPrinter printer;
  try {
    mp::ReadNLFile(filename, printer);
  } catch (const std::exception &exc) {
    std::cerr << exc.what();
  }     
}

gives

Variables:   7
Constraints: 184
Nonzeros:    1130

on your .nl file.

Are you using the latest version of the library from the repo?

[zohannn]

Yes, it is the latest version.
I am currently trying to reproduce the exception outside my software.

[zohannn]

Hi,

here a project you can open with Qt creator. It is a simple form with a push button.
When you push the button, the nl file should be read. However, I get the exception I was talking about.

Could you replicate the error? Please let me know.

Thank you very much.

testQt.zip

[vitaut]

No, I still can't replicate an exception. I get the same output as before when clicking PushButton:

Variables:   7
Constraints: 184
Nonzeros:    1130

[vitaut]

Moreover, I get the same result even without recompiling testQt which suggests that the problem is not due to difference in how libmp is compiled. What OS do you use?

[zohannn]

Linux Mint.
It is very weird. Here a screenshot. To what is the error related ?

[vitaut]

Yes, quite weird. Could you replace line 1066 of mp/nl.h

      ReportError("expected double");

with the following

      ReportError("expected double: '{}' {} {}", fmt::StringRef(ptr_, 10),
                  static_cast<const void*>(ptr_), static_cast<const void*>(end));

recompile, rerun and post the output? This might shed some light on what's going on.

[zohannn]

Here the result.

[vitaut]

One possible explanation for this is that strtod is locale-dependent and you have a locale with , as a decimal separator. As a workaround you can set the locale to C before calling ReadNLFile:

setlocale(LC_NUMERIC, "C");

[zohannn]

The workaround works. I am not sure about the reason of this result, but I will get information about it.
Thank you.

[vitaut]

Great, thanks for the confirmation. I think a better solution is to replace strtod with something locale-independent, so I'll keep this issue open for now.

[zohannn]

Hi Victor,
Now I perfectly understand the problem.

I'll be waiting for your update. Meanwhile I put export LC_NUMERIC="C"
in my .bashrc and it works.

Thank you again.

On 27-01-2016 01:03, Victor Zverovich wrote:

Great, thanks for the confirmation. I think a better solution is to
replace |strtod| with something locale-independent, so I'll keep this
issue open for now.

—
Reply to this email directly or view it on GitHub
#75 (comment).

Gianpaolo Gulletta

[vitaut]

Fixed in 1028153 and two commits after it which implement MSVC compatibility. Thanks again for reporting!