MATLAB: Fitting a lines to a scatter plot

suggestions

Hello,

I am taking a course with a ton of data analysis. I switched over to Engineering Equation Solver just because of the graphing capabilities, however I am not liking the limited options of using an array. The only reason I switched is because I am not too comfortable with plotting data and then fitting a line. Last data analysis assignment I had a lot of problems plotting lines on a scatter plot. What I am going to do now is take the array I have in EES and compress it to a matrix in Matlab.

Can someone explain to me how to fit a variety of trends to a scatter of data?

Best Answer

Fit = polyfit(x,y,1); % x = x data, y = y data, 1 = order of the polynomial i.e a straight line 
plot(polyval(Fit,x))

Related Solutions

MATLAB: I am solving a system of non linear equation using vpasolve but it shows answer as [0*1sym] any other method that I can use

a1 = (-44*Pi^4-1875*P1)*R/(9600*Pi^4*R-1100*Pi^4-75*P3)
a2 = (-1188*Pi^4-625*P2)*R/(19200*Pi^4*R-3300*Pi^4-225*P3)
a3 = R

where

R = roots([2899102924800000000000*Pi^20, -113246208000000000000*Pi^16*((44/3)*Pi^4+P3), 4423680000000000000*((108416/146484375)*Pi^10+(243960584/3515625)*Pi^8+((88/1875)*P1+(594/625)*P2+(814/75)*P3)*Pi^4+P1^2+(1/4)*P2^2+(37/100)*P3^2)*Pi^12, -103680000000000000*((44/3)*Pi^4+P3)*((16153984/10986328125)*Pi^10+(35264208/9765625)*Pi^8+((88/1875)*P1+(396/625)*P2+(44/15)*P3)*Pi^4+P1^2+(1/6)*P2^2+(1/10)*P3^2)*Pi^8, 607500000000000*((44/3)*Pi^4+P3)^2*Pi^4*((30464896/6591796875)*Pi^10-(1931850032/52734375)*Pi^8+((88/1875)*P1+(264/625)*P2+(88/75)*P3)*Pi^4+P1^2+(1/9)*P2^2+(1/25)*P3^2), -86016*(11011*Pi^2-75623375)*Pi^8*(44*Pi^4+3*P3)^3, 11760*Pi^4*(44*Pi^4+3*P3)^4*(121*Pi^2-432125), -(847*Pi^2+125)*(44*Pi^4+3*P3)^5])

... All of the roots. The polynomial is degree 7, so there will be 7 roots, and so 7 solutions to the overall equations.

MATLAB: Energy balance issue with Simscape Heat Exchanger model

UPDATE: I resolved the issue with the energy balance. The heat transfer rate should be calculated as:

Q == epsilon * min(C1,C2) * (T_A1 - T_A2);

And also, I was using counter flow heat exchanger effectiveness formula instead of parallel flow heat exchanger effectiveness. That caused the unphyscial temperature profile of the fluids at outlet. The system and code are both working as expected now. I validated the code and system with the library component of Heat Exchanger (TL-TL).

Hope this helps anyone trying to do similar thing!

Best Answer

Related Solutions

MATLAB: I am solving a system of non linear equation using vpasolve but it shows answer as [0*1sym] any other method that I can use

MATLAB: Energy balance issue with Simscape Heat Exchanger model

Related Question