finding function or equation
finding function or equation
(OP)
Hello
This is my question :
1)We have 1000 inputs. For Example :
input{x_1, x_2, x_3, x_4}
2)And also we have 1000 outputs for our inputs.
For Example :
output{y_1} for input{x_1, x_2, x_3, x_4}
output{y_2} for input{x_5, x_6, x_7, x_8}
3)We have a function or an equation which returns
an output for our inputs.
function : y_1 = f(x_1, x_2, x_3, x_4)
Now :
I need MATLAB to find that function or equation from my
outputs and inputs. I mean :
My inputs are : x_1, x_2, x_3, x_4
My output is : y_1
And desired equation is something like below :
y_1 = f(x_1, x_2, x_3, x_4) =
(x_1^2 + x_2*1/2) - (x_3^3 + x_4)
Thank you so much
Mahdi Heidari
This is my question :
1)We have 1000 inputs. For Example :
input{x_1, x_2, x_3, x_4}
2)And also we have 1000 outputs for our inputs.
For Example :
output{y_1} for input{x_1, x_2, x_3, x_4}
output{y_2} for input{x_5, x_6, x_7, x_8}
3)We have a function or an equation which returns
an output for our inputs.
function : y_1 = f(x_1, x_2, x_3, x_4)
Now :
I need MATLAB to find that function or equation from my
outputs and inputs. I mean :
My inputs are : x_1, x_2, x_3, x_4
My output is : y_1
And desired equation is something like below :
y_1 = f(x_1, x_2, x_3, x_4) =
(x_1^2 + x_2*1/2) - (x_3^3 + x_4)
Thank you so much
Mahdi Heidari





RE: finding function or equation
Where does your input and output data come from? What is the context?
M
--
Dr Michael F Platten
RE: finding function or equation
My Inputs are parameters of a building
which is in fire. Those parameters are :
1) Capacity
2) Fieryness
3) Time of burning
4) area of building
and output is Energy of building which is in fire. I need
a function or an equation to tell me :
A building with above parameter has how much energy ?
For example :
f(Capacity,Fieryness,TimeOfBurning,AreaOFBuilding)=Energy
I have 1000 numbers for any inputs and outputs but I need
a equation for those.
Again thank you.
RE: finding function or equation
If you know you model is simply a low order polyniomial with integre coefficients, then just do a least squares fit. If you have known functions, build your matrices of those functions and do pinv or equivalent.