Qucs - F.A.Q.

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Frequently asked Questions

1. On which OS will Qucs run?
2. What kind of software is need to be installed on my system to run Qucs?
3. Why don't you use Spice to simulate the schematics?
4. Compiling Qucs ends with something like "g++: ./componentdialog.moc.cpp: Can't find file or directory".
5. The ./configure script finds Qt® headers, but cannot locate the libraries. What's wrong?
6. I downloaded and installed the Qucs package on MacOSX, and then when I try to start it the Qucs icon appears in my dock briefly and then disappears and the program quits. What's wrong?
7. How can I set the language for Qucs?
8. Qucs does not start on my MacOSX. What's wrong?
9. What do I do if my question isn't answered here?

Answers

1. On which OS will Qucs run?
Qucs is currently developed on GNU/Linux systems using the GNU autotools. For this reason it is very likely that Qucs runs on all kinds of Unix systems supporting an appropriate system interface and an installed Qt® environment. It has been verified that Qucs can be installed on GNU/Linux, Solaris 2.9, MacOS 10.3, NetBSD, FreeBSD and Cygwin (Unix emulation layer for Windows). With the QT3/Windows Free Edition at hand Qucs is also available natively on Win32 (NT/2000/XP) systems.

2. What kind of software is need to be installed on my system to run Qucs?
So far we only know that Qt® >= 3.1 (and < 4.0.0) by Trolltech® has to be properly installed including headers, libraries and the moc compiler.

3. Why don't you use Spice to simulate the schematics?
There are several debatable reason for this. When looking at the Spice3f.5 source code (i.e. the last version with technical support from the University of California) it seems like the program was made as a proof of concept rather than a ready to use application. In fact the code is not easy to extend though possibly reliable and tested for a great variaty of schematics. The original Spice misses a S-parameter and harmonic balance simulation which may be necessary for microwave engineers, thus Spice would not be an all-in-one solution. Of cource there are trillions of derivates of the last official Spice version extending and bug-fixing it: but which shall we use? Last but not least the licence issue. The copyright holder for the Spice code are the Regents of the University of California. The code comes for free but isn't in fact meant to be re-used.

Some more restriction of Spice3f.5

4. Compiling Qucs ends with something like "g++: ./componentdialog.moc.cpp: Can't find file or directory".
If *.moc.cpp files cannot be compiled the Meta Object Compiler is missing. There was surely the message

...
checking for moc... :
checking for uic... /usr/bin/uic
configure: WARNING:
  The qucs package needs the 'Qt Meta Object Compiler' to compile properly.
  Though Qt itself may be properly installed including headers and libraries
  the 'moc' program is missing.  Possibly you need to install the full
  development package of Qt.
...
during ./configure run. Either moc is not on the system (should not be the case if Qt® is installed) or the environment variable MOC does not exist. Find the location of moc (for Knoppix /usr/bin/moc-qt3 or /usr/share/qt3/bin/moc) and type
	$ export MOC=/usr/bin/moc-qt3
just before calling ./configure.

5. The ./configure script finds Qt® headers, but cannot locate the libraries. What's wrong?
Though the QTDIR environment variable is setup correctly, it may happen that the configure script cannot find the Qt® libraries because it is initially looking for the threaded libraries (the libqt-mt.so link). If you have installed the non-threaded library (the libqt.so link) configure fails. This can be worked around by 

	$ ./configure --disable-mt
On the other hand it may happen that ./configure finds the Qt® headers by chance if the QTDIR environment variable is not setup at all but fails to find the libraries then. Try 
	$ export QTDIR=/path/to/qt

6. I downloaded and installed the Qucs package on MacOSX, and then when I try to start it the Qucs icon appears in my dock briefly and then disappears and the program quits. What's wrong?
The Qucs package for MacOSX requires the QT3.x libraries. The MacOSX versions of the QT3.x libraries are available on the same download site as "minimal" and "complete" package. The "minimal" version is for users who want to use the Qt-based applications available at http://naranja.umh.es/~atg. The "complete" versions is for developers, i.e. including Qt Designer, all example programs and documentation.

7. How can I set the language for Qucs?
If you want to change the language for the Qucs GUI you need to quit Qucs and then 

	$ export LANG=de
for German for example. Then start Qucs again. Also you can change the language in the application settings dialog (in the file menu).

8. Qucs does not start on my MacOSX. What's wrong?
Qucs relies in parts on libraries which are not delivered with MacOSX, but with the X11-installer Apple provides. This does not mean that Qucs on MacOSX runs under X-Windows, the binary installer provided on http://naranja.umh.es/~atg is based on the native version of Trolltech's Qt3.3 framework, but some libs from the X11-packages are used. This is a requirement under MacOSX 10.3 as well as 10.4.x (and it is displayed by the installer before starting the installation). The X11-installer from Apple, which installs the missing libraries, is available from the MacOSX installation CDs/DVD (well, and it is not installed as default when doing a "standard" MacOSX installation). The X11-installer package is available within the optional packages accessible from the MacOSX System installer. If X11 is installed from at least the Apple provided installer, the libs are available.

9. What do I do if my question isn't answered here?
You may go through the mailing list archive. If that doesn't help, contact us.

© 2004, 2005, 2006 Qucs team