2,634 reputation
2033
bio website ephorie.de
location Germany
age 44
visits member for 4 years, 1 month
seen 9 hours ago

just an amateur fascinated by math


Jul
28
awarded  Yearling
Jul
24
comment What are some conceptualizations that work in mathematics but are not strictly true?
That is better :-)
Jul
24
comment What are some conceptualizations that work in mathematics but are not strictly true?
But you didn't say that a line has to be straight.
Jul
24
comment What are some conceptualizations that work in mathematics but are not strictly true?
Whether this is true or not depends on the axiomatic system and how you define "line".
Jul
2
awarded  Curious
Jul
2
awarded  Inquisitive
Jun
4
awarded  Notable Question
May
22
comment What's going on in Ito calculus?
Could you tell us which books did you find and what exactly is missing there?
May
16
asked Why do you need an integral to invert the Z-Transform?
May
15
awarded  Necromancer
May
15
comment Example for finite dimensional analog of integral transforms
I tried this with Mathematica and the vector $\{1,2,3,4,5\}$. The result after multiplying with $B(z)$ and transforming back should be $\{1,1,1,1,1\}$ because these are the first differences, right? (I am not sure about the last one, but anyway). Interestingly after multiplying with $B(z)$ I get $\{1,2,3,4,5\}$ and transforming this back gives the discrete delta function times $\{1,2,3,4,5\}$: wolframalpha.com/input/… - what's wrong?!?
May
15
comment Example for finite dimensional analog of integral transforms
This is exactly what I was looking for! Thank you very much indeed! :-)
May
15
accepted Example for finite dimensional analog of integral transforms
May
14
comment Example for finite dimensional analog of integral transforms
@MattL. Ok, I tried this with vectors but there are still things that don't work out :-( If you gave me an example with the z-transform on vectors where multiplication/division becomes differentiation/integration I would happily accept your answer :-) Thank you
May
14
reviewed Approve suggested edit on Why does $\sin(0)$ exist?
May
14
comment Discrete Laplace Tranform.
I asked a similar question here: math.stackexchange.com/questions/793550/… - what I find strange though is that while you can also read that the Laplace transform is the continuous analog of the dot product for infinite dimensional vectors (=functions) you still calculate infinitely many terms in the discrete version (and not just over the available dimensions of your vectors as with the dot product) - perhpas you could contribute :-)
May
14
comment Discrete Laplace Tranform.
I asked a similar question here: math.stackexchange.com/questions/793550/… - what I find strange though is that while you can also read that the Laplace transform is the continuous analog of the dot product for infinite dimensional vectors (=functions) you still calculate infinitely many terms in the discrete version (and not just over the available dimensions of your vectors as with the dot product) - perhpas you could contribute :-)
May
14
comment Example for finite dimensional analog of integral transforms
@MattL.: Thank you, what still bothers me with this finite version is that the sum is over infinitely many terms because the dot product is only over the available dimensions.
May
13
reviewed Approve suggested edit on Trigonometric substitution
May
13
comment Example for finite dimensional analog of integral transforms
@MattL.: I had a quick look at it and it looks promising - so first thank you! Could the $z$ also be real valued like e.g. $2$?