Change initial conditions to maximize Rsquared

For example is there a way to tell matlab + or - these varaibles (X,Y,Z) by 0.001 as needed to maxamize the R squared value??

Such as a while loop that looks like this? this is a made up script for an example

X1 = 1

Y1 = 1

Z1 = 1

X2 = 1

Y2 = 1

Z2 = 1

Fit = fitlm(A,B);

R2 = Fit.Rsquared.Ordinary; ( gets an R squared lets assume not 1)

while R2 < 0.8

dx = 0.001 ( I want this dx to be + or - 0.001 somehow in order to maxamize R squared (R2))

X1 = X1 +dx

Y1 = Y1+dz

Z1 = Z1+dx

..... same for X2 Y2 Z2

A = sin(X1+Y1+Z1)

B=sin(X2+Y2+Z2)

Fit = fitlm(A,B);

R2 = Fit.Rsquared.Ordinary;

end