I am digitizing data from two plots. What I need is Lift vs Angle and Drag vs Angle. The plots I have are Lift vs Angle and Drag vs Lift. In theory there should be enough information there for me to get what I need, but I'm struggling. I tried a simple interp1 function and got NaNs as well as values that clearly didn't make sense:
cd = interp1(clcd(:,1),clcd(:,2),avscl(:,2)
where clcd is a 67×2 matrix with lift in the first column and drag in the second, and avcl is a matrix with angle in the first column and lift in the second (I also tried reordering the lift values from the avscl in increasing order to match the lift axis in the Lift vs Drag curve but predictably just got the same values in a different order). And I also tried to resample to get drag at evenly spaced lift values but just got a single constant value:
resample(clcd(:,2),clcd(:,1),f)
where f was something like 1/10 or 1/100 etc…
I attached my workspace as well as the curves I am digitizing from so you can see what I mean (it's the top two plots in the picture, and clincr is lift in increasing order).
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