# can anyone help me please ?

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Commented: David Fletcher on 28 Mar 2018
can anyone solve me this problem, ican't detect the error ?
D=0;
d=0.3;
if th==7.5
(D=d/0.6); %&& (K==0.15);
else if th==7.8
(D=d/0.5); %&& (K==0.2)
else if th==8
(D=d/0.4); %&& (K==0.26);
else if th==8.5
(D=d/0.3); %&& (K==0.31);
else if th==9
(D=d/0.2); %&& (K==0.36);
else th==9.5
(D=d/0.1); %&& (K==0.41);
end
end
end
end
end
L=(D-d)/(2*tan((th/2)*(pi/180)));
##### 2 CommentsShowHide 1 older comment
David Fletcher on 28 Mar 2018
It's a personal thing I suppose but I tend to find switch - case blocks easier to follow than nested if-elseif blocks
switch round(th*10)
case 75
D=d/0.6
case 78
D=d/0.5
case 80
D=d/0.4
case 85
D=d/0.3
case 90
D=d/0.2
case 95
D=d/0.1
end

Star Strider on 28 Mar 2018
First, remove the parentheses around the ‘D’ assignments in the if block,
Second, your if block elseif statements will only execute if ‘th’ is exactly equal to the values you test. If ‘th’ are not exactly equal to them, they will be evaluated with the else condition:
D = d/0.1;
If ‘th’ can only take certain discrete values, then your code will likely do what you want.
If ‘th’ is continuous, consider testing for ranges of ‘th’:
if th <= 7.5
D=d/0.6; %&& (K==0.15);
elseif (th > 7.5) & (th <= 7.8)
D=d/0.5; %&& (K==0.2)
... and so for the rest of the ‘elseif’ tests
end