asked on

Delphi 7 TDBChart

Dear Experts.

I have a database application in Delphi 7.
Am using TDBChart to plot averages from the DB.
I am using a TLineSeries to plot these averages.

Is there a way to eliminate abnormal high spikes on the Chart?
Cause I am analyzing massas of data and maybe on record are way out high which in return
pushes the average up.

calinutz

Maybe if you do a function for regularizing the results or add conditions to your Query... because the DBChart does not know that it bothers you to have too big values in it. Also you can play with the scaling of the DBChart to increase the maximum on the vertical, that would probabely lead to a smoothing of the chart.

Regards.

TheRealLoki

Personally, I would add a "calculated" field to the query (double click on the TQuery, new field, "calculated")
"Nice_Big_Value"

then add click on the Query component, and add an OnCalcFields event

procedure TForm1.Query1CalcFields(DataSet: TDataSet);
begin
Dataset.FieldByName('Nice_Big_Value').AsFloat := max(1000, Dataset.FieldByName('NORMAL_Big_Value').AsFloat); // max of 1000
// same as Query1NiceBigValue.AsFloat := max(1000, Query1Normal_Big_Value.AsFloat);
end;

then in your dbchart, use Nice_Big_Value instead of Big_Value

TheRealLoki

sorry, it should be MIN, not max as in
:= MIN((1000, Dataset.FieldByName('NORMAL_Big_Value').AsFloat);

TheRealLoki

btw, you need to add "math" to your uses clause

Marius0188

ASKER

Thanks for help so far.

When I draw a TLineSeries chart based on averages of thousands of record's data it is very spiky.
I do not want to manipulate the actual data but would rather draw a very smooth line chart.
For example: In stock exchange you get Moving Averages. I need to draw the same smooth line.
Is there a series that can do this or how will I go about doing this?

Marius0188

ASKER

Maybe I am not clear enough.

Instead of the spikes going up and down accross the X axis I would like to draw a smooth line.

ASKER CERTIFIED SOLUTION

TheRealLoki

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Marius0188

ASKER

Yes I think what I need is your second explanation.
The curve fitting.

TheRealLoki

there's a teechart pro trial version you can download, but I don't think you'll get this feature for free in teechart any time soon

Marius0188

ASKER

1. Where can I download Teechart Pro Trial?
Do you have an url for me please.

2. Isn't there any other free charting components for Delphi that might assist me?
Please provide urls for download etc...

calinutz

For teechart Pro evaluation check out this link:
http://www.steema.com/downloads/dwn_tch_vcl.html

As for other delphi charting components that are free and also provide lot of functionalities there isn't any. At least none that I know of, and I know I checked a couple of times in all the right places.
Best place I've found is this:
http://www.torry.net/pages.php?id=195

Regards