Re: In search of elegant indices searching

Dear Tim,

I am a bit tired today and the task is a little involved,
so I try to let others work for me
I want to evaluate some mathematical function , which has
arguments βxβ,βyβ,βzβ etc. (think of something like

(x,y,z) -> 5zy+x*y**2)

)
at different values for these variables x,y,z.
Actually, Iβve got data, and I am trying to get back that function, or
an
approximation to it, from these data, so itβs actually a (multivariate)
interpolation problem. To do that efficiently, I need to hold
several variable values fixed at some point in time while varying
others.

So, in my example, if I have a Hash like

my_hash={βxβ,[1,1,3,1,5,6],βwβ,[1,2,3,1,4,5],βyβ,[1,1,1,4,4,6]} ,

then these are coordinates where the unknown function is evaluated at.

If, now, the nice and wonderful method I search for, gives me

res={{βxβ=>1,βwβ=>1}=>[0,3],{βxβ=>3,βwβ=>3}=>[2],{βxβ=>5,βwβ=>4}=>[4],{βxβ=>6,
βwβ=>5}=>[5]},

I know that at the 0-th and 3-th measurement point, βxβ and βwβ didnβt
vary,
so, any
change in the function values is due to the change of βyβ from 1 to 4.

Do you have any elegant ideas for that ?

Thank you,

Best regards,

Axel

my_hash={βxβ,[1,1,3,1,5,6],βwβ,[1,2,3,1,4,5],βyβ,[1,1,1,4,4,6]} ,

res={{βxβ=>1,βwβ=>1}=>[0,3],{βxβ=>3,βwβ=>3}=>[2],{βxβ=>5,βwβ=>4}=>[4],{βxβ=>6,
βwβ=>5}=>[5]},

I know that at the 0-th and 3-th measurement point, βxβ and βwβ didnβt vary,
so, any change in the function values is due to the change of βyβ from 1 to 4.

I still donβt get it:

{βxβ=>1,βwβ=>1}=>[0,3]
means the 0th and 3rd point are both β1β

{βxβ=>3,βwβ=>3}=>[2]
means the 2nd point is 3 in both

{βxβ=>5,βwβ=>4}=>[4]
now it gets weird, this means the 4th position of x is 5 and of w is
4β¦ Why only that result? Seems a little arbitrary, why doesnβt the
result contain:
{βxβ=>1,βwβ=>2}=>[1]
?

And how come `y` is left out of the results alltogether?