qwt

tutorial on graphs plotting qwt [closed]

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问题 As it currently stands, this question is not a good fit for our Q&A format. We expect answers to be supported by facts, references, or expertise, but this question will likely solicit debate, arguments, polling, or extended discussion. If you feel that this question can be improved and possibly reopened, visit the help center for guidance. Closed 7 years ago . I am using qt and qwt. I want to plot a graph but I am completely new to it. Can some one please give me a link which explains basic

Tool tip to show plot values in Qwt

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问题 I have a qwt plot in my application. I want to show a small tool tip to show the value of the point at which mouse is pointed on the curve. I found that I have to use QwtPlotPicker for this, but couldn't find any proper example to implement this in my code. I am new to Qwt so it would be great if anyone could help me solve this problem. Thanks, Rakesh. 回答1: The author himself says here: A QwtPlotPicker gives you the current position of the mouse ( in screen and plot coordinates ). Then you

Qt, VS2005, Qwt - Can't use Q_OBJECT in class derived from Qwt widgets

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问题 We've compiled QT 4.6 and QWT 5.2.0 for VS2005. We're trying to derive a class from QwtDial, and the derived class has slots. So, we need to add the Q_OBJECT macro. However, when we do that, the linker chokes out this error: error LNK2001: unresolved external symbol "public: static struct QMetaObject const QwtDial::staticMetaObject" (?staticMetaObject@QwtDial@@2UQMetaObject@@B) I've looked at the Qwt.dll with depends, and it has that function. Looking at the .lib file with a hex editor shows

Plot Spectrum in real time?

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问题 I would like to add and plot the spectrum of signal on Qwt Oscillocope's example. My Idea is to create another seriesData class. SerieData. I wonder if there will not conflict between sample of SeriesData and sample of Signaldata or I just need to modify the signaldata? Any help and Advice would be appreciated. Thanks 回答1: input signal is usually in form of cyclic buffer the output buffer can be static one. This applies also for time domain plots. Without actually see your structures is

plotting real time Data on (qwt )Oscillocope

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问题 I'm trying to create a program, using Qt (c++), which can record audio from my microphone using QAudioinput and QIODevice. Now, I want to visualize my signal Any help would be appreciated. Thanks [Edit1] - copied from your comment (by Spektre) I Have only one Buffer for both channel I use Qt , the value of channel are interlaced on buffer this is how I separate values for ( int i = 0, j = 0; i < countSamples ; ++j) { YVectorRight[j]=Samples[i++]; YVectorLeft[j] =Samples[i++]; } after I plot

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一、 1.下载地址 https://sourceforge.net/projects/qwt/ 2.用Qt打开qwt.pro,选择MSVC2017_32bit编译。 3.把生成的文件\designer\plugins\designer\qwt_designer_plugin.dll 复制到D:\ProgramFiles\Qt5.13.2\Tools\QtCreator\bin\plugins\designer 下面，打开Qt界面设计就可以看到有此插件。 4.lib\qwt.dll和lib\qwtd.dll 复制到D:\ProgramFiles\Qt5.13.2\5.13.2\msvc2017\bin； lib\qwt.lib和lib\qwtd.lib复制到D:\ProgramFiles\Qt5.13.2\5.13.2\msvc2017\lib； 5.在D:\ProgramFiles\Qt5.13.2\5.13.2\msvc2017\include新建一个文件qwt，把所有的头文件拷贝到此目录下。 6.新建Qt项目，在pro添加DEFINES += QT_DLL QWT_DLL 库引用： win32:CONFIG(release, debug|release): LIBS += -LD:/ProgramFiles/Qt5.13.2/5.13.2/msvc2017/lib/ -lqwt

Slow replot of a Qwt graph in embedded linux

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问题 I'm facing some problems while developing an Qt-based embedded solution for Linux. Basically my application plots a QwtPlot graph with up to 8 QwtPlotCurves attached to it. A QwtPlot::replot() is called each 1 second. Data arrives from a socket connection connected to another .c app in the same system. Hardware is a Texas' OMAP. The problem is that depending on the configuration, the replot becomes very, very slow. To be more specific, if I put 4 curves to be shown, no delay is perceived, but

Qt binary linked to both Qt 5 and (wrongly) to Qt 4 causing segmentation fault when linked to Qwt

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问题 I have a Qt / ROS / Qwt application. Everything was going fine until I tried to link to Qwt. Note that I'm using Qwt 6.1.2 which should run on Qt 5.5. Indeed, the examples run fine. When I run my binary, it crashes even if I'm not using Qwt. I just need to link the my code to Qwt for that to happen. And -here is the issue I think-, gdb gives the following error: ram received signal SIGSEGV, Segmentation fault. 0x00007ffff25eadfc in ?? () from /usr/lib/x86_64-linux-gnu/libQtGui.so.4 Which is

Is this method of inter-thread-communication safe?

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问题 I have 3 objects(inherited from QObject ) that each contain a separate std::list . Each object gets created in the main gui thread (with no parent) and then is pushed to it's own thread (using Qt's QObject::moveToThread() ). Each thread is hooked up to a gui and messages are sent between the different threads with data. Each thread is to essentially handle it's own list. For example: Obj 1 : Consumer of data. It pop's the front off of its list(if data is present) to use. It also has a SLOT

Segfault when adding Qwt plot to layout

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问题 I try to build chart demo using Qwt and C++. I've added the following code to button click handler: QwtPlot *plot = new QwtPlot(QwtText("Demo")); plot->setGeometry(0, 0, 100, 100); QwtPlotCurve curve("Sine"); QVector<double> xs; QVector<double> ys; for (double x = 0; x < 100; x++) { xs.append(x); ys.append(sin(x)); } QwtPointArrayData *series = new QwtPointArrayData(xs, ys); curve.setData(series); curve.attach(plot); plot->show(); QLayout *lay = ui->centralWidget->layout(); lay->addWidget