How to replace number scale with text scale in qwtplot?

[npatil15]

Hello,

I have draw simple graph using QwtPlot() and QwtPlotGrid().

Now I want to replace numbers on Y-axis with some text.

Please check the below attachment shows, I have achived right side of graph now I want graph looks like left side.
graph.jpg

Thanking in advanced!

[Uwe]

Overload QwtScaleDraw::label.

Uwe

[npatil15]

Thanks Uwe, it will work, but I have some issues while working on.
I have tried to overload like below,

class QwtMyScaleDraw: public QwtScaleDraw
{
public:
QwtMyScaleDraw(){
 
}
 
virtual QwtText label(double v) const
{
qDebug()<<"Input to Label"<<v;
}

class QwtMyScaleDraw: public QwtScaleDraw
{
public:
QwtMyScaleDraw(){

}

virtual QwtText label(double v) const
{
qDebug()<<"Input to Label"<<v;
}

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And I use this above class as,

plot->setAxisScaleDraw(QwtPlot::yLeft, new QwtMyScaleDraw());

plot->setAxisScaleDraw(QwtPlot::yLeft, new QwtMyScaleDraw());

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Actual Output ==>
unknown(0)[11756]: Input to Label 0
unknown(0)[11756]: Input to Label 100
unknown(0)[11756]: Input to Label 10
unknown(0)[11756]: Input to Label 20
unknown(0)[11756]: Input to Label 30
unknown(0)[11756]: Input to Label 40
unknown(0)[11756]: Input to Label 50
unknown(0)[11756]: Input to Label 60
unknown(0)[11756]: Input to Label 70
unknown(0)[11756]: Input to Label 80
unknown(0)[11756]: Input to Label 90
unknown(0)[11756]: Input to Label 1000
unknown(0)[11756]: Input to Label 0
unknown(0)[11756]: Input to Label 200
unknown(0)[11756]: Input to Label 400
unknown(0)[11756]: Input to Label 600
unknown(0)[11756]: Input to Label 800

Why this first 12 lines of output in above? and from where that 100 comes in betwen 0 and 10 every time?

Expected Output ==>
unknown(0)[11756]: Input to Label 0
unknown(0)[11756]: Input to Label 200
unknown(0)[11756]: Input to Label 400
unknown(0)[11756]: Input to Label 600
unknown(0)[11756]: Input to Label 800
unknown(0)[11756]: Input to Label 1000

These creates an issue because I want to add text labels to a line that is visible in the graph, and from the above outputs, I didn't able to understand which is visible line and which is not.
I have a list of text labels that I want to assing to each line which is visible in the graph (This I can manage to do).

---

Added after 44 minutes:

By using below code, now its resolve, I'm getting expected output.

plot->setAxisAutoScale(Qt::Axis::YAxis, false);

plot->setAxisAutoScale(Qt::Axis::YAxis, false);

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But their is little change in the output,

Actual Output ==>
unknown(0)[11756]: Input to Label 0
unknown(0)[11756]: Input to Label 1000
unknown(0)[11756]: Input to Label 200
unknown(0)[11756]: Input to Label 400
unknown(0)[11756]: Input to Label 600
unknown(0)[11756]: Input to Label 800

Here above 1000 is comming between 0 and 200. Which causing my string list little disturb.

Expected Output==>
unknown(0)[11756]: Input to Label 0
unknown(0)[11756]: Input to Label 200
unknown(0)[11756]: Input to Label 400
unknown(0)[11756]: Input to Label 600
unknown(0)[11756]: Input to Label 800
unknown(0)[11756]: Input to Label 1000