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carlao
54 Posts |
 Posted - 20 Mar 2005 : 11:16:24
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I created a multiline chart with scroll that works fine. I also created a multiaxes with multiline that also is ok. But now I need a chart that be multiline and multiaxes with horizontal scroll. I create this chart based on the others one that I mentioned above, but the behavior is not correct. First, only the first line is being scrolled. The others are freeze. How can I scroll all lines and update the y axes also?
Here is the snippet code to scroll the chart.
public void UpdateXScaleAndAxes(int index)
{
int startindex = index;
pTransform[0].SetScaleStartX( (double) startindex);
pTransform[0].SetScaleStopX( (double) (startindex + 100));
XAxis.CalcAutoAxis();
XAxisLab.CalcAutoAxisLabels();
for(int i=0; i < nTraces; i++)
{
((LinearAxis)yAxis[i]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[i]).CalcAutoAxisLabels();
}
}
Any idea?
Thanks.
Carlos
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quinncurtis
1164 Posts |
Posted - 20 Mar 2005 : 12:21:32
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My guess is that since you are only changing the starting and ending values of the first coordinate system, i.e. pTransform[0] in your example:
pTransform[0].SetScaleStartX( (double) startindex);
pTransform[0].SetScaleStopX( (double) (startindex + 100));
that only the line plot associated with that coordinate system is scrolling.
Seems like your code should be doing something like:
for(int i=0; i < nTraces; i++)
{
pTransform[i].SetScaleStartX( (double) startindex);
pTransform[i].SetScaleStopX( (double) (startindex + 100));
}
// These two objects reference pTransform[0]
XAxis.CalcAutoAxis();
XAxisLab.CalcAutoAxisLabels();
If you look at our OHLCFinPlot example again you will see that we change the starting and ending x-values of all coordinate systems in the chart in response to a scrollbar change.
Also, in the future, when you post a problem, such as the AxisTitle topic you posted, please post on the same thread how the problem was resolved in order to aid other programmers with the same problem.
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carlao
54 Posts |
Posted - 20 Mar 2005 : 14:37:46
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I think that this is not an easy task. The main problem here is to understand how it works. I took a look at OHLCFinPlot example but could not fix the problem yet. I have 5 lines with 4 Y axis at left and the last one at right. When I run the code below, only the Y axis at right (the last line) stay fixed. The others Y axis are moved with the lines. How to lock the right Y axis to not move the scrolling the lines?
Carlos
{
int startindex = index;
for(int i=0; i < nTraces; i++)
{
pTransform[i].SetScaleStartX( (double) startindex);
pTransform[i].SetScaleStopX( (double) (startindex + 100));
}
XAxis.CalcAutoAxis();
XAxisLab.CalcAutoAxisLabels();
((LinearAxis)yAxis[1]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[1]).CalcAutoAxisLabels();
((LinearAxis)yAxis[1]).SetAxisIntercept(pTransform[1].GetStartX()-50);
((LinearAxis)yAxis[1]).SetAxisTickDir(ChartObj.AXIS_MAX);
for(int i=2; i < nTraces-1; i++)
{
((LinearAxis)yAxis[i]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[i]).CalcAutoAxisLabels();
}
((LinearAxis)yAxis[nTraces-1]).SetAxisIntercept(pTransform[nTraces-1].GetStopX());
((LinearAxis)yAxis[nTraces-1]).SetAxisTickDir(ChartObj.AXIS_MAX);
chartVu.UpdateDraw();
} |
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quinncurtis
1164 Posts |
Posted - 20 Mar 2005 : 15:06:22
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I'm not sure if I understand what you say. Your question was
"How to lock the right Y axis to not move the scrolling the lines? ".
Did you mean to say,
"How do I lock the LEFT Y-Axes to not move with the scrolling lines."
You must specify a new, adjusted, axis intercept for each y-axis. Your code specifies a new intercept for yAxis[1] and yAxis[nTraces-1], but no others.
((LinearAxis)yAxis[1]).SetAxisIntercept(pTransform[1].GetStartX()-50);
.
.
.
((LinearAxis)yAxis[nTraces-1]).SetAxisIntercept(pTransform[nTraces-1].GetStopX());
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carlao
54 Posts |
Posted - 21 Mar 2005 : 21:15:24
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After many try and fail I could arrive in the code below
public void UpdateXScaleAndAxes(int index)
{
int startindex = index;
for(int i=0; i < nTraces; i++)
{
pTransform[i].SetScaleStartX( (double) startindex);
pTransform[i].SetScaleStopX( (double) (startindex + 100));
}
XAxis.CalcAutoAxis();
XAxisLab.CalcAutoAxisLabels();
((LinearAxis)yAxis[0]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[0]).CalcAutoAxisLabels();
((LinearAxis)yAxis[0]).SetAxisIntercept(pTransform[0].GetStartX());
((LinearAxis)yAxis[0]).SetAxisTickDir(ChartObj.AXIS_MIN);
for(int i=1; i < nTraces-1; i++)
{
((LinearAxis)yAxis[i]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[i]).CalcAutoAxisLabels();
((LinearAxis)yAxis[i]).SetAxisIntercept(pTransform[0].GetStartX()-i*16.7);
((LinearAxis)yAxis[i]).SetAxisTickDir(ChartObj.AXIS_MIN);
}
((LinearAxis)yAxis[nTraces-1]).SetAxisIntercept(pTransform[nTraces-1].GetStopX());
((LinearAxis)yAxis[nTraces-1]).SetAxisTickDir(ChartObj.AXIS_MAX);
chartVu.UpdateDraw();
}
But I have a little problem yet. See that I am using the value 16.7 to separate y axis from each other. The problem is that this value is not exactly the same used by the code to construct the chart. That way, when I execute the code above for the first time the Y axis are moved a little bit. Maybe one pixel or two but it is visible. How can I use the same value used by the code to separate each Y axis when the chart is constructed?
Thanks.
carlao
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quinncurtis
1164 Posts |
Posted - 21 Mar 2005 : 22:46:05
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There is always going to be rounding error, which can go either way on pixel boundaries, so a shift of one pixel may be unavoidable. Your second loop goes one count too far.
public void UpdateXScaleAndAxes(int index)
{
int startindex = index;
for(int i=0; i < nTraces; i++)
{
pTransform[i].SetScaleStartX( (double) startindex);
pTransform[i].SetScaleStopX( (double) (startindex + 100));
}
XAxis.CalcAutoAxis();
XAxisLab.CalcAutoAxisLabels();
((LinearAxis)yAxis[0]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[0]).CalcAutoAxisLabels();
((LinearAxis)yAxis[0]).SetAxisIntercept(pTransform[0].GetStartX());
((LinearAxis)yAxis[0]).SetAxisTickDir(ChartObj.AXIS_MIN);
// for(int i=1; i < nTraces-1; i++) // replace with below
for for(int i=1; i < nTraces-2; i++)
{
((LinearAxis)yAxis[i]).CalcAutoAxis();
((NumericAxisLabels)yAxisLab[i]).CalcAutoAxisLabels();
((LinearAxis)yAxis[i]).SetAxisIntercept( pTransform[0].GetStartX()-i*16.7);
((LinearAxis)yAxis[i]).SetAxisTickDir(ChartObj.AXIS_MIN);
}
((LinearAxis)yAxis[nTraces-1]).SetAxisIntercept(pTransform[nTraces-1].GetStopX());
((LinearAxis)yAxis[nTraces-1]).SetAxisTickDir(ChartObj.AXIS_MAX);
chartVu.UpdateDraw();
}
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Topic |
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problems with scroll
