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Claire
Delphi Developer 
Sat, 17 Mar 2001 03:00:00 GMT

Claire
Delphi Developer 
Sat, 17 Mar 2001 03:00:00 GMT
Algorithm needed for counting peaks on chart
Does anyone know of an algorithm to count no of peaks on a line/bar
chart Thanks in advance.  Claire 
Earl F. Glyn
Delphi Developer 
Sat, 17 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartQuoteClaire wrote in message ... looking for, there are several possible approaches. Have you considered thresholding? Just plot (internally) a new If you have a function, y = f(x), the max and min points are Could you give a specific example of your data? That might efg Earl F. Glynn EMail: EarlGl...@att.net 
Clair
Delphi Developer 
Sun, 18 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartHi Earl, The data is acquired from measuring high voltage discharges during a . How could I smooth the curves in this ? My maths is rather stale. 
Earl F. Glyn
Delphi Developer 
Sun, 18 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartQuoteClaire wrote in message ...  I approximated you curve mathematically with the function Take a look at the table below for the (X,Y) values. The Note: View the following tables with a fixedwidth font X Y Slope Sign 1 > 1 Assume No Noise 2 peaks Quote>How could I smooth the curves in this ? My maths is rather stale.  To approximate this mathematically, let's take the same If you apply the "No Noise" approach from above, you'll X Y Y Smooth Slope Sign 1 > 1 So, how you handle the "noise" in your data If you'd like the Excel 97 spreadsheet with the efg Earl F. Glynn EMail: EarlGl...@att.net 
Geoge Privalo
Delphi Developer 
Mon, 19 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartQuoteClaire wrote: eliminate "grass". After that take the first derivative and check for changing sign on it from + to . George 
Jeremy Collin
Delphi Developer 
Mon, 19 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartQuoteDenis Jeanroy wrote in message <6utubl$bs...@aristote.pratique.fr>... of each peak as you go, and rank the results, or filter out peaks that are "too small" after you've finished. This allows the user to specify the height at which peaks are interesting, rather than relying on a hard coded algorithm. It would also be fairly simple to make your algorithm less sensitive by comparing with a wider range of points on either side. This would automatically allow the user to perform a simple sensitivity analysis on the results by specifying different ranges. Watch out for that algorithm, though, as it'll crash when it tries to  
paul.harring..
Delphi Developer 
Tue, 20 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartIn article <efptVCA+jIE2E...@hallworthhome.demon.co.uk>, Claire <clair...@hallworthhome.demon.co.uk> wrote: Quote> Does anyone know of an algorithm to count no of peaks on a line/bar will probably do the job quite well. To jog your memory, create a duplicate set of figures, but when making the duplicate, set each value to the average of its own value plus the value before it and after it. If this is not effective, you may include more than one value before and after the current value, (ie. a five reading moving average.) eg. NewValue[i] := (OldValues[i2] + OldValues[i1] + OldValues[i] + Of couse, with an AC cycle, you will end up with a slightly lower peak value. Hope this is useful, == Posted via Deja News, The Discussion Network == 
Claire Humphre
Delphi Developer 
Wed, 21 Mar 2001 03:00:00 GMT
Re:Algorithm needed for counting peaks on chartThank you everyone for your help :) Kind Regards  A very smiley Claire Software Engineer email : Cla...@HallworthHome.demon.co.uk 
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