QCustomPlot | Plotting Widget form http : //www.WorksLikeClockwork.com | Widget library

You need to install both python-sip and sip otherwise the setup will fail:

The most direct approach to solve your issue might be to define a minimum size for your QCustomPlot Widget. This can easily achieved with the following reduced example. Actually, the problems has nothing to do with QCustomPlot at all. It could have been any kind of widget with minimum size (0,0).

The QCPGraph seems to be used for sorted data with only value per key. From QCustomPlot documentation, it looks like the QCPCurve would be a better match in order to plot a trajectory graph (multiple value for the same key).

From the QCPCurve description:

Unlike QCPGraph, plottables of this type may have multiple points with the same key coordinate, so their visual representation can have loops. This is realized by introducing a third coordinate t, which defines the order of the points described by the other two coordinates x and y.

The QLineEdit gives you a QString containing a math expression. This type cannot be converted to a double unless it contains nothing but a double. For example, the text "10.34" can be converted from a QString to a double, but the text "10.34 - 18 + 2" cannot, because it must be evaluated first.

You need to pass the QLineEdit text to a math expression parser. You could write your own if you only need to handle simple arithmetic. This is a worthwhile learning exercise, and you can find numerous examples online, including on SO. If you need more sophisticated parsing, or are in a hurry, then you can google for C++ math parser or similar and use existing code.

Go to this folder

C:\Program Files (x86)\Windows Kits\10\bin\10.0.17763.0\x86

and copy rc.exe and rcdll.dll to the following folder

X64

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin\x86_amd64

X86

C:\Program Files (x86)\Microsoft Visual Studio 14.0\VC\bin

QCPItemLine is drawn automatically without replot, if you want it not to be displayed you must use:

You have to set a different layer to each item, and then you can use moveLayer() to move the layers.

According to QCustomPlot forums (https://www.qcustomplot.com/index.php/support/forum/670), currently there's no any built-in functionality for this.

General workaround seems to be something like this:

1. Substitue "key" values with actual continuous data (one may use just plain integer indexes 0..N).

2. [Optional] Save a "mapping" to and from original key values.

3. [Optional] Subclass QCPAxisTickerDateTime (or general QCPAxisTicker) and implement custom method for creating tick labels, using previously mapped keys.

QApplication takes argc by reference and expects this reference to be valid for the lifetime of the application. Once your Plot function ends, QApplication is left with a dangling reference to gui_argc so when the call to QApplication::arguments (as seen in your back trace) is made, undefined behavior occurs. You can fix this by making argc persistent somewhere.