qwt

[Vincenzo]

Hi, I have gentoo linux, and I emerged qwt 5.0.2-r1 without any problem.
But it doesn't work for me.
For this short program:

#include <QApplication>
#include <qwt_plot.h>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QwtPlot plot; // ! here i tryed the qwt
    return app.exec();
}

#include <QApplication>
#include <qwt_plot.h>
int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    QwtPlot plot; // ! here i tryed the qwt
    return app.exec();
}

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...I get this reply:

g++ -c -pipe -O2 -march=pentium-m -fomit-frame-pointer -pipe -march=pentium-m -msse2 -Wall -W -D_REENTRANT -DQT_NO_DEBUG -DQT_GUI_LIB -DQT_CORE_LIB -DQT_SHARED -I/usr/share/qt4/mkspecs/linux-g++ -I. -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtCore -I/usr/include/qt4/QtGui -I/usr/include/qt4/QtGui -I/usr/include/qt4 -I/usr/include -I/usr/include -I/include -I. -I. -o hello.o hello.cpp
hello.cpp:3:22: error: qwt_plot.h: No such file or directory
hello.cpp: In function 'int main(int, char**)':
hello.cpp:9: error: 'QwtPlot' was not declared in this scope
hello.cpp:9: error: expected `;' before 'plot'
make: *** [hello.o] Error 1

I followed this tutorial
...that means, i did the following steps:
$ echo "/usr/lib" >> /etc/ld.so/conf

...and than without any IDE, i did next:
# qmake -project

...the .pro file i edited like this:

TEMPLATE = app
TARGET =
DEPENDPATH += .
# i'm not sure which is correct of following
INCLUDEPATH += /usr/include /usr/local/include $(QWT)/include
LIBS += -lqwt
 
# Input
SOURCES += hello.cpp

TEMPLATE = app
TARGET =
DEPENDPATH += .
# i'm not sure which is correct of following
INCLUDEPATH += /usr/include /usr/local/include $(QWT)/include
LIBS += -lqwt

# Input
SOURCES += hello.cpp

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...than
# qmake -o makefile hello.pro
...After the make command I get the result which is quoted upper.

...I checked my direcotoryes:
in usr/lib i have the following files
libqwt.so
libqwt.so.5
libqwt.so.5.0
libqwt.so.5.0.2

in usr/local/include i have the qwt5 directory with header files.

My question is: What did i wrong? Yes surelly i'm newbie, that's the reason why i posted it here. Also sorry for my english..

[wysota]

Do you have the header files installed? Where is qwt_plot.h located in your system?

By the way, please give a more descriptive title to the thread next time...

[Vincenzo]

the qwt_plot.h i have in /usr/include/qwt5
...sorry for the title

[wysota]

Add this to your .pro file:

INCLUDEPATH+=/usr/include/qwt5
LIBS += -lqwt

INCLUDEPATH+=/usr/include/qwt5
LIBS += -lqwt

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and rerun qmake. You might have to replace -lqwt with -lqwt5 depending on what is the library called on your system.

[Vincenzo]

thank you very much!!! It works! )
...i never managed .pro files, always left it to IDE

once again: thank you!

[wysota]

...i never managed .pro files, always left it to IDE

In that case tell your IDE to look for includes in /usr/include/qwt5 and link with the qwt library.