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print surface fit equation in python

python,numpy,matplotlib,scipy,least-squares
I'm trying to fit a surface model to a 3D data-set (x,y,z) using matplotlib. Where z = f(x,y). So, I'm going for the quadratic fitting with equation: f(x,y) = ax^2+by^2+cxy+dx+ey+f So far, I have successfully plotted the 3d-fitted-surface using least-square method using: # best-fit quadratic curve A = np.c_[np.ones(data.shape[0]), data[:,:2],...

How to use least squares method in Matlab?

matlab,math,curve-fitting,least-squares,best-fit-curve
I have 37 linear equations and 36 variables in the form of a matrix equation; A*X=B . The equations don't have an exact answer. I want to use Matlab least square method to find the answers with the least error. I am new to Matlab so any comments will help....

Least squares for circle detection

python,algorithm,feature-detection,least-squares
I'm trying to perform a circle detection from a laser scan using least squares optimization over a subset of data points. Since the measurements are only obtained for a part of a circle, the least squares method returns faulty result, reporting a circle much closer to the laser than it...

least-squares method with a constraint

matlab,math,curve-fitting,linear-programming,least-squares
I have 37 linear equations with 36 variables in the form of matrix: A x = b. (A has 37 rows and 36 columns.) The equations don't have an exact solution so I have used Matlab to find the closest answer using x = A \ b. The problem is...

Calculating 'hat' matrix in R

r,lm,least-squares
In calculating the 'hat' matrix in weighted least squares a part of the calculation is X^T*W*X However, I am unsure how one would do this in R See the following example: x <- matrix(c(1,2,3,4,5,6),nrow=3,ncol=2,byrow=T) xt <- t(x) w <- as.vector(c(7,8,9)) xt*w%*%x Which gives the error: Error in xt * w...

MATLAB polynomial fit selective powers

matlab,least-squares,polynomials
I have 2 vectors x and y to which I want to fit a polynomial as y = f(x) in MATLAB. I could have used polyfit. However, I want to fit only selective power terms of the polynomial. For example, y = f(x) = a*x^3 + b*x + c. Notice...

How to solve for matrix in Matlab?

matlab,matrix,least-squares
How can I solve , where and and in the least squares sense in matlab? So I'd like to have the minimizing as output....

how to solve many overdetermined systems of linear equations using vectorized codes?

multidimensional-array,scipy,vectorization,linear-algebra,least-squares
I need to solve a system of linear equations Lx=b, where x is always a vector (3x1 array), L is an Nx3 array, and b is an Nx1 vector. N usually ranges from 4 to something like 10. I have no problems solving this using scipy.linalg.lstsq(L,b) However, I need to...