/sci/ - Science & Math

[Anonymous No.4635727]

Say, I need a function f(x), which accepts "x" {from 1 to 100} as input and outputs value "y" {from 14 to 8500}.
How do I approach the problem, if I want "y" to be linearly dependent on "x"? And what if I want a logarithmic relation between these?

[Anonymous No.4635734]

bumo

[Anonymous No.4635735]

y=c+k*exp(x)

[Anonymous No.4635740]

f(x) = ax + b

solve, for a and b, the system
14 = a*1 + b
8500 = a*100 + b

[Anonymous No.4635748]

>>4635740
Oh, nice.
What about non-linear relation?

[Filosofer scientist linguist No.4635757]

>>4635748
Download the program "Graph" and plot in ur numbers. Use insert trend-line and select the function type u want.

[Anonymous No.4635766]

You want a curve that passes through all the points or one that fits better the shape of the distribution of points?

[Anonymous No.4635767]

>>4635748
There are a lot of interpolation methods, >>4635740 being a direct approach. For a non-linear equation, you merely tack on constants and shit (y=a+bx+cx^2+dx^3+...), obviously with the appropriate number of solution sets to generate the appropriate number of equations so you can solve the constants.

[Anonymous No.4635777]

>>4635767
>>4635757
>>4635766
Okay, thanks. How do I solve this in Mathematica?
I have studied linear systems long ago.

[Anonymous No.4635778]

>>4635766
One that fits the shape.

[Anonymous No.4635783]

>>4635777
Well you could make a matrix out of it and have Mathematica get the reduced echelon form, I think that would be the quickest. I don't know how Mathematica works but I'd assume it's more like MATLAB and less like Wolframalpha.

[Anonymous No.4635836]

>>4635783
Can this be the right setup? I have quickly followed the guide, but I am confused by how Mathematica assigns x,y,a,b to which tensors.

[Anonymous No.4635868]

>>4635836
Nice.