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33s - programming question - Frank Rottgardt - 05-15-2008

Is there a simple way to get access to the content of the data registers holding the values for statistic calculation? (data you enter with Sigma +)I do not mean the six registers 28 - 32, but the list of values representing the population or sample.

I need to calculate "Sigma x^3" and the default statistic functions only give me "Sigma x^2". Is it possible to program a loop starting at i=1 to i=n where I can read the list content value by value, raising it to 3 and STO+ in a variable representing "Sigma x^3" when the loop-routine reached its end?

I know I could write an input-loop to enter the sample values not making use of "Sigma+" to get around the problem. But I would like to stick to the generic statistic input routine with the "Sigma+" which enables me to do further calculations with the "onboard" statistic functions.


Re: 33s - programming question - Frank Rottgardt - 05-15-2008

Maybe writing an own input-routine where I can enter the sample-value, making the x^3 and STO+ to get Sigma x^3 and in parallel add the entered sample-value x to the statistc-matrix with a programmed "Sigma+" ?


Re: 33s - programming question - Stefan Vorkoetter - 05-15-2008

Like virtually all calculators, the HP 33s doesn't actually store the entered data anywhere. All it does is accumulate the various sums in the statistics registers.

Writing your own input routine, something like this, is probably the best way to go:

LBL S
ENTER
3
y^x
STO +K
RDN
Sigma+
RTN

This is similar to what I do in my curve fitting program for the HP 35s, where I need to accumulate not only the normal six statistics values, but also:

Sigma ln(x)
Sigma ln(y)
Sigma x ln(y)
Sigma y ln(x)
Sigma ln(x)^2
Sigma ln(y)^2
Sigma ln(x) ln(y)

Stefan


Re: 33s - programming question - Frank Rottgardt - 05-15-2008

Thanks, Stefan

seems to be plain and simple.




Re: 33s - programming question - Don Shepherd - 05-15-2008

Quote:
Like virtually all calculators, the HP 33s doesn't actually store the entered data anywhere. All it does is accumulate the various sums in the statistics registers.

The 17bII+ acutally does store the data items in a SUM list, and the contents of the SUM list is accessible within a Solver equation. And it does offer the standard statistical calculations (although I have never used them).