# ± use in MATLAB

47 views (last 30 days)
Priyank Goel on 27 Feb 2021
Edited: Star Strider on 27 Feb 2021
CL = (0.331±0.008) + (0.15±0.002)*ALPHA
I have to code this equation in MATLAB but don't know, how can I code this?
Thanks!

Star Strider on 27 Feb 2021
One option:
CL = [(0.331+0.008) + (0.15+0.002)*ALPHA
(0.331-0.008) + (0.15-0.002)*ALPHA];
Experiment to get different results, depending on how you want to define the equations.
Star Strider on 27 Feb 2021
It’s quite possible to make this ridiculously complicated.
The easiest option is likely:
CL = [0.331 0.15] + [0.008 0.002].*[1 1; 1 -1; -1 1; -1 -1];
and just let it go at that.
EDIT — (27 Feb 2021 at 22:04)
Those are obviously only the limits, according to whatever criteria you wish to apply to them. Use them appropriately in your code.

Walter Roberson on 27 Feb 2021
syms ALPHA
syms delta_1 delta_2
assume(-0.008 <= delta_1 & delta_1 <= 0.008)
assume(-0.002 <= delta_2 & delta_2 <= 0.002)
CL = 0.331 + delta_1 + (0.15+delta_2)*ALPHA
CL =
expand(CL)
ans =
The matrix approach is not correct, as it gives specific values, whereas you need a range of values. For example you might have 1/(CL-0.15*ALPHA-0.331) as part of an expression, and if you only work with the edge cases you miss the fact that this passes through 1/0 .