MATLAB: Finding the equation of a line passing 2 points

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Hello, I have two points (x1,y1) and (x2,y2). Now I want to find the linear equation of a line passing through these 2 points. The equation must be like f(x)=a*x+b. Is there any function in matlab that accepts coordinates of two points an gives the related linear equation back? If not, I know that a=(y2-y1)/(x2-x1) but what is the short and easy way to find 'b'? Thanks in advance!

Best Answer

Try polyfit:

coefficients = polyfit([x1, x2], [y1, y2], 1);
a = coefficients (1);
b = coefficients (2);

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A = importdata('VERY_EXPENSIVE.txt');
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% 
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hold on
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MATLAB: MATLAB — how to create a parabolic arc

hi,

The parabola's equation is defined y=ax²+bx+c, you need to set the coefficients a,b,and c so as the line passes through the three points x1,x2 and x3 :

 x1=[0,0];
 x2=[5,5];
 x3=[10,0];
 Y=[x1(2);x2(2);x3(2)]
A=[x1(1)^2 x1(1) 1;x2(1)^2 x2(1) 1;x3(1)^2 x3(1) 1]
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figure, plot(x,Y), grid on, 
hold on
text(x1(1),x1(2), ' POINT X1')
text(x2(1),x2(2), ' POINT X2')
text(x3(1),x3(2), ' POINT X3')
hold off

Best Answer

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