Draw geometric curve of Quadratic equation Here is a simple quadratic equation: Draw its geometric curve by wolfram. We can use Table to calculate all discrete values in special range. Table[2*x^2 + 1, {x, -10, 10}] {201, 163, Read more…
Sometimes we need to check character encoding for special word, or by contrast, to input some special words according to character encoding. The article will show you how to handle the two situations. Find the character encoding for special world Read more…
Open multiple files Open multiple files on the horizontal direction: vim -o file1 file2 file3 ….Switch edit file：ctrl + ww.Close all opened files without saving operation：qa.Multiple fails in the vertical direction: vim -O file1 file2 file3 ….Add a number n after -o, we can open Read more…
Borderless window: setWindowFlags( Qt::FramelessWindowHint ); Set background color: QPalette pal = mainWin->Getui().qvtkWidget->palette(); pal.setColor( QPalette::Background, Qt::black ); setAutoFillBackground( true ); this->setPalette( pal ); Make window stay on the top level: setWindowFlags(Qt::WindowStaysOnTopHint) Remove maximize button in widget： setWindowFlags( this->windowFlags() & ~Qt::WindowMaximizeButtonHint ); Read more…
The interfaces can imitate users’ operations. QTest::keyClick QTest::keyPress QTest::mouseClick QSignalSpy listens for signal emission, it is a list of QVariant lists. It will not shield off signal to make slot invalid. QCheckBox *box = …; QSignalSpy spy(box, SIGNAL(clicked(bool))); //… QList Read more…
Development environment: VTK-8.1.1 macOS 10.14.4 Qt 5.11.2 Clang 8.1.0 package for vtk program use otool command tool to find all depent library files for executable. otool -L exe Then we can redirect all output logs into a local file and Read more…
Simple Unit Test Project Let’s create a new unit test project firstly. Write our test functions in feild private Q_SLOTS for the class. tst_string.cpp: #include <QString> #include <QtTest> class String : public QObject { Q_OBJECT public: String(); private Q_SLOTS: void Read more…
accumulate Interval algorithm accumulate supports custom calculate method to count elemeints in the special range. We can use it to get summary, multiple, average and etc of some elements, it’s very convenient and powerful. The syntax and usage example are Read more…
count STL algorithm count can help us to count the elements that are equal to value.Its syntax is like the following form: C++ template typename iterator_traits::difference_type count( InputIt first, InputIt last, const T &value ); Example: C++ #include #include #include Read more…