Search found 40 matches

by rawi
Fri Sep 10, 2021 6:57 pm
Forum: Discuss!
Topic: Standard error of forecast
Replies: 10
Views: 742

Re: Standard error of forecast (error propagation in fitting?)

Hi Walter, I fear I do not understand you well. The formula I gave is not the standard value of the sample values but for a value x0 that may be a sample value or may not be. I do not know what t is and 2,0.683 Is a typo by sure but even if I read it as 2 I cannot see why this multplication makes se...
by rawi
Sat Sep 04, 2021 12:18 pm
Forum: Discuss!
Topic: Standard error of forecast
Replies: 10
Views: 742

Re: Standard error of forecast (error propagation in fitting?)

Hi Walter, s(e) should not be replaced by s(y). In the wikipedia article sigma is defined only implicitly. Under the headline "t-test" you see it is assumed that the error term is normally distributed with mean 0 and variance sigma^2. From this it is clear that the sigma used later is the ...
by rawi
Fri Sep 03, 2021 7:52 am
Forum: Discuss!
Topic: Standard error of forecast
Replies: 10
Views: 742

Re: Standard error of forecast (error propagation in fitting?)

Hi Pierre, your formula delivers the standard error of all y-values of the regression, one result for all y-values together (see the example in Excel). The formula I posted delivers the standard error for one single value which may be in the data set of the regression analysis but may as well be an ...
by rawi
Thu Sep 02, 2021 8:24 pm
Forum: Discuss!
Topic: Standard error of forecast
Replies: 10
Views: 742

Re: Standard error of forecast (error propagation in fitting?)

Hi Walter, the formula for the variance of a forecasting value f is: S(f)^2 = S(e)^2 * (1+(1/N) + (x0-mean(x))^2/sum(xi-mean(x))^2) Whereas: N = number of observations mean(x) = arithmetic mean of x x0 = value of x for which you want a forecast Se^2 = sum(yi-(a+b*xi))^2/(N-2) a is the constant, b th...
by rawi
Sat Aug 28, 2021 3:46 pm
Forum: Software Library
Topic: Crypting and decrypting text messages
Replies: 0
Views: 162

Crypting and decrypting text messages

With this program you can crypt and decrypt text messages. This is the DM 42 version of a DM 41 X program that can be found here: https://forum.swissmicros.com/viewtopic.php?f=30&t=3095 Application: At the beginning you are asked for the starting value of the random number generator: SEED? Take ...
by rawi
Sat Aug 28, 2021 10:46 am
Forum: User Software Contributions
Topic: Encryption and decryption of text
Replies: 0
Views: 158

Encryption and decryption of text

This program allows to encrypt and decrypt messages. Application: At the beginning you are asked for the starting value of the random number generator: SEED? Take any number between 0 and 1. The same number has to be used for encryption and decryption. Then you are asked whether you want to encrypt ...
by rawi
Mon Aug 09, 2021 9:51 am
Forum: Usage tips, tricks and problem reports
Topic: Problem with input of numeric label
Replies: 3
Views: 236

Re: Problem with input of numeric label

Thank you very much for your answer, it worked.
And sorry that I did not realize that it was already discussed. I did not know that it was discussed there.

Best

Raimund
by rawi
Mon Aug 09, 2021 8:09 am
Forum: Usage tips, tricks and problem reports
Topic: Problem with input of numeric label
Replies: 3
Views: 236

Problem with input of numeric label

Hi, whenever I want to input a numeric label in my DM 42 (by pressing f PGM.FCN - LBL or XEQ f ALPHA LBL) the Alpha-Mode is switched on. In the lowest line of the screen the Alphabet is shown above the 6 top line keys and the sign |A| is in the first line of the screen. I am not able to switch off t...
by rawi
Sat Jul 31, 2021 9:24 am
Forum: DM1x/DM41
Topic: DM15L_M1B and Matrix limits
Replies: 1
Views: 214

Re: DM15L_M1B and Matrix limits

Hi Boub65, you are right: The manual for the HP 15 C states, that there can be a total of 64 matrix elements, that can be used for 1 matrix or distributed to up to 5 matrices. On Swiss micros webiste (found here: https://www.swissmicros.com/product/dm15l ) there is only the limitation that the maxim...
by rawi
Tue Jul 27, 2021 7:44 am
Forum: Discuss!
Topic: May 2021 Speculations
Replies: 162
Views: 26824

Re: May 2021 Speculations

Boub65 wrote: I just hope it's a landscape calculator... Perhaps you are right. Perhaps it is a DM 42 L? There already was a prototype: https://www.youtube.com/watch?v=314JMYJEh6k This would make sense because the 42 has the solve and integrate function included and can handle matrix and imaginary n...