## More functions

Ideas and wishes for TeeChart
nisbus
Newbie
Posts: 18
Joined: Wed Jan 18, 2006 12:00 am
Location: Iceland
Contact:

### More functions

Hi,

I've written a few extra functions for my application but the problem is that when I set the chart to live update those series of course don't update like the built in functions.

The ones I've built in and would like to see are:

Percentage change (I'm actually amazed that this one isn't already there)
Minus last period
Linear regression
EWMA
GARCH
y=mx+b
X12 ARIMA (method available as a program at U.S. Census bureau.)

It would also be nice if one could have a statistics object of a series that gave basic statistics of the series:

Skewness
Kurtosis
Slope
y-intercept
etc.

thanks,
nisbus

Narcís
Posts: 14730
Joined: Mon Jun 09, 2003 4:00 am
Location: Banyoles, Catalonia
Contact:
Hi nisbus,

It would be really helpful if you could provide use some information or URL about each series specification.

Regarding your series not updating as built-in series, if you are a sourcecode customer you could check how TeeChart implements its functions.

Best Regards,
 Narcís Calvet / Development & Support Steema Software Avinguda Montilivi 33, 17003 Girona, Catalonia Tel: 34 972 218 797 http://www.steema.com Instructions - How to post in this forum

nisbus
Newbie
Posts: 18
Joined: Wed Jan 18, 2006 12:00 am
Location: Iceland
Contact:
Here are some resources where you can find information on these functions.

Percentage change : Simply subtract the old value from the new value, then divide by the old value. Multiply the result by 100 and slap a % sign on it.

Minus last period : used for series with a datetime x axis, just start at y[1] and subtract the value with y[0] etc.

Linear regression : http://en.wikipedia.org/wiki/Linear_regression
EWMA : http://www.itl.nist.gov/div898/handbook ... pmc324.htm (this is actually a great page for statistics and math formulas)
GARCH/ARCH : http://www.mathworks.com/products/garch/
y=mx+b : http://mathforum.org/cgraph/cslope/mxplusb.html
X-12 ARIMA : http://www.census.gov/srd/www/x12a/

Skewness: http://en.wikipedia.org/wiki/Skewness
Kurtosis : http://en.wikipedia.org/wiki/Kurtosis
Slope & y-intercept : http://www.math.com/school/subject2/les ... 4L2GL.html

I will most definitely be looking into the TeeChart implementation of functions.

thanks,
nisbus

Narcís