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11-Garnet
Mar 24, 2023 10:52 AM UTC
Solved

Convert a regressive function to a matrix

I have a regressive function Y[k and i need to express it as a matrix. Ultimately, I need to smooth it and make it a continuous function using either linear interpolation or splines.

 

Note that the regressive function is expressed using subscripts, y[k.

 

I'm using Mathcad Prime

 

LucMeekesAnswer
23-Emerald V
Mar 25, 2023 1:55 PM UTC

Like this:

LucMeekes_0-1679752483459.png

Success!
Luc

 

7 replies

Werner_E
25-Diamond I
Mar 24, 2023 11:00 AM UTC

Note that the regressive function is expressed using subscripts, y[k.

 


Then its not a function but rather a vector of values!?

Its not clear to me what you are looking for.

How about posting a example worksheet?

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gatlas11-GarnetAuthor
11-Garnet
Mar 25, 2023 11:50 AM UTC

Werner,

 

I'm trying to convert a regressive function y[k to a smoothe function that can be readily differentiated.

 

Please see the attachment.

 

Thanks,

Glen

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LucMeekes23-Emerald VAnswer
23-Emerald V
Mar 25, 2023 1:55 PM UTC

Like this:

LucMeekes_0-1679752483459.png

Success!
Luc

 

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terryhendicott
21-Topaz II
Mar 24, 2023 3:55 PM UTC

Hi perhaps answer can be found on these help locations:

Regression

Interpolation and Prediction Functions

Beyond this you may need to expand the question

Capture2.JPG

Capture.JPG

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Werner_E
25-Diamond I
Mar 25, 2023 5:34 PM UTC

Because your recursively defined series follows a linear recursion, we can always find the direct general formula for computing the nth term as a function of n,
So there is no need for interpolation or approximation via a regression.

Werner_E_2-1679765588698.png

Don't let the imaginary unit confuse you, the returned function values are real 😉

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gatlas11-GarnetAuthor
11-Garnet
Mar 25, 2023 7:07 PM UTC

Thanks!

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