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Guest

I have a TChart and one button in a project. The button just plots
points to the chart. If I call the AddXY() function it bombs if the
data is from an array created outside this routine or it bombs if the
"Y" data is a constant like dVal = 18100. NOTE: If the dVal = 1817 it
won't bomb, if dVal = 1818 it will bomb.
( dVal = 0x71A; //0x71A (1818)fails //0x719 (1817) passes )

Any ideas why this occurs? The only difference I can see is that one
is calculated on the fly and the other is known by the compiler at
compile time(this doesn't explain why dVal < 1817 passes but dVal >=
1818 fails though)
Thanks...

void __fastcall TForm1::Button2Click(TObject *Sender)
{
int i;
int iVal;
double dVal;

//dVal = 18180; // Bombs, when used
for(i=0;i<10000;i++)
{
//dVal = 8000; // Bombs, when used
//dVal = i*sin(i*3.14/360); // Works, when used
tcDataPlot->Series[0]->AddXY(i,dVal,"",clBlue); //i,10000,"",
clBlack);
}

}

//---------------------------------------------------------------------------

"Access violation at address 40901083 in module 'tee60.bpl'. Write of
address 01754000"

"Project test.exe raised exception class EInvalidPointer with message
'Invalid pointer operation'. Process stopped"

Clayton Arends · Guest

I own TeeChart pro 7 so I don't know if you are experiencing a bug in the
standard version. With that in mind I tested your code by creating a new
application. I dropped a TChart on the form, added a "point" series,
dropped a button and added the following to the button handler:

void __fastcall TForm1::Button1Click(TObject *Sender)
{
TChartSeries* series = Chart1->Series[0];
series->Clear();

double dVal;
for (int i = 0; i < 10000; ++i)
{
dVal = i * sin(i * 3.14 / 360);
series->AddXY(i, dVal, "", clBlue);
}
}

This code worked fine as well as any value I used for dVal including 18100
and 1818. Have you altered the chart settings in any way? If so, please
copy the chart from the IDE and paste it into your reply so that I can see
the object code for the chart.

Note, I also tried the above using a "line" series instead of the "point"
series with no problems.

- Clayton

PS - borland.public.cppbuilder.language.cpp is not the best newsgroup for
questions such as this. For future questions on TeeChart you should post to
borland.public.cppbuilder.vcl.components.using,
borland.public.cppbuilder.thirdpartytools, or post to Steema's forums at
http://steema.com. Steema is the company that makes TeeChart.