Solving equation problem
Solving equation problem
(OP)
Hi. I would like to calculate an equation with variables in range of values (in Given - Find block), but I have problem with that. Let me explain on example what I'm talking about. I write:
y=1..4 (range of values for variable y)
Given
x(y)=1 (initial guess)
x(y)=2*x(y)+1 (logical equation)
r(y)=Find(x(y))
When i type "r(y)=" Mathcad report a problem: "initial guess must consist of numbers and matrices". I don't know how exactly i should change the initial guess. Any idea ? Thanks for help.
y=1..4 (range of values for variable y)
Given
x(y)=1 (initial guess)
x(y)=2*x(y)+1 (logical equation)
r(y)=Find(x(y))
When i type "r(y)=" Mathcad report a problem: "initial guess must consist of numbers and matrices". I don't know how exactly i should change the initial guess. Any idea ? Thanks for help.





RE: Solving equation problem
Steve
RE: Solving equation problem
RE: Solving equation problem
Back to your problem though, could the issue be that your guess value is apparently a function x(y)=1.
RE: Solving equation problem
RE: Solving equation problem
RE: Solving equation problem
RE: Solving equation problem
RE: Solving equation problem
blah = 2*blah+1 blah = -1 always
TTFN
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RE: Solving equation problem
y=1..4 (range of values for variable y)
Given
x=1 (initial guess)
y(x)=2*x(y)+1 (logical equation)
r(y)=Find(x(y))
How about that ?
RE: Solving equation problem
y=1..4 (range of values for variable y)
Given
x=1 (initial guess)
y=2*x(y)+1 (logical equation)
r(y)=Find(x(y))
Somebody know what is wrong with this ?
RE: Solving equation problem
> You cannot place an undefined function on the right hand side of ANY definition or constraint
> In your specific example x(y) should simply be x
> However, our construct has a closed form solution of the apparent function inversion that you appear to be looking for, so a given-find is a rather tedious way of finding the answer, and will not give you the functional relationship, in any case:
x = (y-1)/2
This is the type of problem that you could the symbolic functionality of Mathcad, as opposed to the numerical functionality.
TTFN
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RE: Solving equation problem
RE: Solving equation problem
Given
y:=1 (initial guess - y)
x:=1 (initial guess - x)
y=2*x+1 (logical equation) (relation)
r(y)=Find(x)
then
y:=1..4 (range of values for variable y)
r(y)=
RE: Solving equation problem
What does x have to do with this?
Peter Nachtwey
Delta Computer Systems
http://www.deltamotion.com
RE: Solving equation problem
r(y) = y/2 - 1/2
See Quicksheets Solving Equations, Symbolic Solutions of Equations.
RE: Solving equation problem
Regards
Mike