wonderful piece of work. Dear Prof, How can I get Multilinear models - four regressor variables (x1; x2; x3 & x4) with Surface Fitting Tool in Matlab? To get Polynomial of second order : y = B + a1(x1)^2 + a2(x2)^2 +a3(x3)^2+a4(x4)^2 + a5(x1)(x2) + a6(x1)(x3) + a7(x1)(x4)+a7(x2)(x3)+a8(x2)(x4)+a9(x3)(x4) and how to use cftool Please give me some introduction to do this or any hint. Thanks a lot.
Thanks for the message but I don’t have experience working with radiosonde data. You could try to use multivariable linear regression fitting on the data and get the coefficients from the results because the regression would provide those constants.
@@davidbarnwelljr103 because we want to get the slope. We use the left divide to solve the simultaneous equations in the form of a matrix to calculate it.
@@YusriYusup Ahh, thanks.. but in the second b. The b in which the y intercept is not zero. Why is this value thw y intercept, 1.427120171726537? While this value, 0.000001256394274 is the slope? I'm still trying to figure that and the purpose of the ones vector?
wonderful piece of work. Dear Prof, How can I get Multilinear models - four regressor variables (x1; x2; x3 & x4) with Surface Fitting Tool in Matlab?
To get Polynomial of second order : y = B + a1(x1)^2 + a2(x2)^2 +a3(x3)^2+a4(x4)^2 + a5(x1)(x2) + a6(x1)(x3) + a7(x1)(x4)+a7(x2)(x3)+a8(x2)(x4)+a9(x3)(x4) and how to use cftool
Please give me some introduction to do this or any hint.
Thanks a lot.
how can I calculate the least square and mean squared error from multivariable regression?
I don’t know from the top of my head because I don’t memorize the functions, but the specific functions to calculate them should be built in MATLAB.
I have radiosonde temperature data upto 30 km. h=bo +b1QBO +b2ENSO +b3SSN +b4IOD, how can I get bo,b1,b2,b3 and b4? thank you
Thanks for the message but I don’t have experience working with radiosonde data. You could try to use multivariable linear regression fitting on the data and get the coefficients from the results because the regression would provide those constants.
Do you have a copy of the data set you used?
Hi, the data is built-in MATLAB.
@@YusriYusup Thanks very much.
Sorry can I ask one more question? Why did you use mldivide in calculating b1?
@@davidbarnwelljr103 because we want to get the slope. We use the left divide to solve the simultaneous equations in the form of a matrix to calculate it.
@@YusriYusup Ahh, thanks.. but in the second b. The b in which the y intercept is not zero. Why is this value thw y intercept, 1.427120171726537? While this value, 0.000001256394274
is the slope? I'm still trying to figure that and the purpose of the ones vector?
please could you send me code for 3 D (thank you lot)