xBottom Scale Overide

Hi All,

How can i move scale 1 to the middle of 0 and 1?

(explaination)
I am plotting data from a sensor from each device ( say two devices in this case )

so in my plot I use xBottom scale as my device number and made sure that all sensor points (data) from device 1 will stay in 0 to 1 tick in my plot, and the data from device 2 will be ploted in 1 to 2 tick.

Now, I'd like to move the label to the middle of the block not at the edge. say number 1 the x scale should be drawn in between 0 and 1 tick.

hoping you understand what i am talking about,

baray98

You want a label for the interval, not for a position ( on my TODO list since some time ). This is not possible with Qwt 5.x, but you can implement the following workaround:

With QwtPlot::setAxisScaleDiv you can assign scales with irregular tick positions. The labels are always below the major ticks.
Assign minor ticks at 0 and 1 and a major tick at 0.5. Then set the tick length for major ticks to 0 and increase the tick length for the minor ticks ( QwtScaleDraw::setTickLength() ).

HTH,
Uwe

Quote:

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Assign minor ticks at 0 and 1 and a major tick at 0.5.

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Can you give a little snippets on how to do this on QwtScaleDiv. I did not really understand it

My devices are actually 128 and each devices will have a max sensor of 48. If there is a little something that i can start with QwtScaleDiv then I can figure out the rest.

baray98

Its a class with the min/max values of your scale and 3 arrays with the values, where the ticks are. Nothing that could be misunderstood.

Uwe

Hi Uwe,

I got it running on single plot but when i tried to incorporate it to the "plot matrix" example where , x axis are sycnhronize, it did somehow went back ot its regular ticks. This only happens when i would play with the setAxisScale or change the axisScale on xBottom of the matrix.

Any hint of whats going on ? whos putting the regular ticks back?

baray98

p.s. thank you very much for your help

I have a related question, on the same subject:

I can't seem to locate QwtScaleDraw::setTickLength() in the documentation and I also didn't understand the suggested use of this method as you described it.

Could anyone please explain what that method can be used for and how?

how to getaxis scaling range.
i want to get the min and max range of the x-axis .How can we do that?

Don't ask a new question in an existing thread. Start a new one.

To answer your question:

Code:

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double axisLeft = plot->axisScaleDiv( QwtPlot::xBottom )->lBound();
double axisRight = plot->axisScaleDiv( QwtPlot::xBottom )->hBound();

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