Not enough is a bit vague. Can you be more specific ?

I found the problem Problem was that I think : I receive 65536 point but my widget width only 2000px and 32.768(33) point equal 1px, I lost the peak value there. That is my opinion and I solved. If you are think problem is different. I listen. Windows 11 Qt 6.9.x Qwt-6.3.0

AFAIK, the qwt do not published wit the cmake support. It has only the qmake configuration.

Hi, @WLOrion said in Introduction in Qwt: I didn't know this behavior of the Qwt Classes. This is nothing Qwt specific, it's part of the C++ basics. As for tutorial, there's a nice online book that is in German but the author claims that online translator should give you a good enough result in your own language.

@BJUN Hi and welcome to devnet forum qwt is an extension of Qt as third party library. It maintains its own mailing list. Please check out there. This might be a faster way to get feedback on the issue.

ok, stupid me! I forgot to include Qwt in the *.pro file: ... CONFIG += qwt INCLUDEPATH +="/usr/include/qwt" LIBS += -L/usr/lib -lqwt

@mrjj Thank you sir for helping me and direction. I am able to solve this issue by setting the clipping area properly on graph. Use QWidget::update() instead of QWidget::repaint().

@Yash001 Hi, i wish i knew the answer but im fairly sure canvas()->width(); just returns the actual widget size and not the zoomed area as such. Had a look in the help but didnt find the answer on how to get the extent on a zoomed canvas.

@DSpider great! please don't forget to mark your post as solved. Thanks.

@SGaist got it.

Perhaps some dll files are missing.

User something like LIBS += -F /path/to/where/qwt_framework_is -framework qwt

@SGaist It worked. Thank you so much.

@vassia Thanks for reply and good to know that I could help. Since the issue has been solved for you, please mark also your post as solved. This helps others to see that there might be a solution. In order to mark as solved, go to the compobox named "Topic Tools" after your first post or after the last post in the thread and select "Mark as Solved".

[image: Untitled.jpg] Edit: Fixed link to image -- @Wieland

Hi to all, I succeded in extracting from the data contours as path. Anyone knows how to plot them using qt charts? http://doc.qt.io/qt-5/qtcharts-areachart-example.html I need to create area charts with empty areas inside.