Simple plotting problem of a function

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Isa
Isa on 23 Oct 2012
Hi, I am new at Matlab and I want to plot a graph of a spring's displacement in relation with the person height (H). I wrote the following in the MatLab editor (The three important lines are the three last ones) :
rad=pi/180; %To convert degress into radiant
deg=180/pi; %To convert radiant into degrees
C1=0.088*H+0.03;
C2=0.036*H+0.04;
C3=0.02*H;
C4=0.153*H;
teta1=360-118-90-atan(C1/C4)*deg-atan(C2/C3)*deg;
teta2=360-80-90-atan(C1/C4)*deg-atan(C2/C3)*deg;
PO=sqrt(C1^2+C4^2);
AO=sqrt(C2^2+C3^2);
L1=sqrt(PO^2+AO^2-2*PO*AO*cos(teta1*rad));
L2=sqrt(PO^2+AO^2-2*PO*AO*cos(teta2*rad));
SpringDisplacement=L2-L1;
H=1:0.01:2;
ezplot('SpringDisplacement(H)');
The error message when I press RUN MATLAB is : ??? Undefined function or method 'Matlab' for input arguments of type 'char'. And I do not know when I should use ezplot or plot? I am really new at this program so explanation of my errors would be greatly appreciated! Thank you,
  1 Comment
Isa
Isa on 23 Oct 2012
So I put . after so each elements of the list are squared instead of matrix multiplications. Also using plot() after the changes made it work .
rad=pi/180; %To convert degress into radiant
deg=180/pi; %To convert radiant into degrees
C1=0.088*H+0.03;
C2=0.036*H+0.04;
C3=0.02*H;
C4=0.153*H;
teta1=360-118-90-atan(C1/C4)*deg-atan(C2/C3)*deg;
teta2=360-80-90-atan(C1/C4)*deg-atan(C2/C3)*deg;
PO=sqrt(C1.^2+C4.^2);
AO=sqrt(C2.^2+C3.^2);
L1=sqrt(PO.^2+AO.^2-2*PO.*AO.*cos(teta1*rad));
L2=sqrt(PO.^2+AO.^2-2*PO.*AO.*cos(teta2*rad));
SpringDisplacement=L2-L1;
H=1:0.01:1.9; %Min height of person is 1m, maximum height is 1.9m
plot(SpringDisplacement,H)
The values from the plot seem to correspond with what I am looking for so I am assuming it is right

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