improve the auto scaling of axis

[21did21]

Hello,

now, i plot curve with a logarithmic X axis:

myplot->setAxisScaleEngine(QwtPlot::xBottom, new QwtLog10ScaleEngine)

myplot->setAxisScaleEngine(QwtPlot::xBottom, new QwtLog10ScaleEngine)

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the result is not very nice:

the original scale is between 1e-100 and 1, if autoscale works nice is not a problem for me but, there is a problem.
my values are between 1 and 2 and during the ploting the scale stay between 1e-100 and 1e20, So my curve is like a vertical line

=> how i can modify this? can we fix originals boundaries for this autoscaling?

[21did21]

excuse me for this thread
=> i have a 0 for the first value it's the problem

see you

---

Added after 1 25 minutes:

finally i haven't already a problem:

i use this to plot my curve:

for (int z=1;z<timeNb6;z++)
           {
                if (Points2_OneXtwoY[z][0]<0.002)
                {
                }
                else
                {
                x6 << Points2_OneXtwoY[z][0] ;
                y6 << Points2_OneXtwoY[z][1] ;
                x7 << Points2_OneXtwoY[z][0] ;
                y7 << Points2_OneXtwoY[z][2] ;
                }
           }
           AtomicCurve1.setSamples(x6.data(),y6.data(),x6.size());
           AtomicCurve2.setSamples(x7.data(),y7.data(),x7.size());

for (int z=1;z<timeNb6;z++)
           {
                if (Points2_OneXtwoY[z][0]<0.002)
                {
                }
                else
                {
                x6 << Points2_OneXtwoY[z][0] ;
                y6 << Points2_OneXtwoY[z][1] ;
                x7 << Points2_OneXtwoY[z][0] ;
                y7 << Points2_OneXtwoY[z][2] ;
                }
           }
           AtomicCurve1.setSamples(x6.data(),y6.data(),x6.size());
           AtomicCurve2.setSamples(x7.data(),y7.data(),x7.size());

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So in my plot i can't have a point for x6 or x7 with a value less than 0.002, but in my plot i have a value less than 0.002

Please see my curve result

http://imageshack.us/photo/my-images/804/myplot.jpg/

[Uwe]

So in my plot i can't have ...

Of course you can - your debug code is wrong.

Uwe

[21did21]

thank you for your answer, but i haven't understand it

=> if i put this condition (less than 0.002) so i shouldn't have a value less than this 0.002 in my plot

[Uwe]

C/C++ arrays start with index 0.

Uwe

[21did21]

thank, but yes i know this but it don't resolve my problem

i just put z=1 for the first loop because i don't want to plot first value

for (int z=1;z<timeNb6;z++)

for (int z=1;z<timeNb6;z++)

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[d_stranz]

So where do you check the other values to make sure they are not < 0.002? You only check the [z][0] element.

And do you clear all of your x, y arrays before pushing new data into them?

[21did21]

my problem is solve:

in fact, i did not clear vector before push. So now it's works nice

thanks for your help