If function in matlab

I am using the following if function / formula in excel.

=IF(A1>292.5,"NW", IF(A1>247.5,"W", IF(A1>202.5,"SW",IF(A1>157.5,"S",IF(A1>112.5,"SE",IF(A1>67.5,"E",IF(A1>22.5,"NE")))))))

I have written the following code:

for k=1:I

if M16>292.5

fprintf('SW\n')

elseif (M16<292.5>247.5)

fprintf('W\n')

elseif (M16<247.5>202.5)

fprintf('SW\n')

elseif (M16<202.5>157.5)

fprintf('S\n')

elseif (M16<157.5>112.5)

fprintf('SE\n')

elseif (M16<112.5>67.5)

fprintf('E\n')

elseif (M16<67.5>22.5)

fprintf('NE\n')

elseif (M16<22.5>0)

fprintf('N\n')

else

'invalid'

end

end

I am not getting proper result. Can anyone help.

Regards and thanks in advance

[Omer Yasin Birey]

What is this double comparisons. Such as

(M16<292.5>247.5)

Obviously 292.5 is greater than 247.5, I don't understand why are you comparing them. And regardless of the correctness of the comparison, I believe each line that has these kind of comparisons will return 0. Meaning that the code will never explore inside the if's.

[Mohana]

What i meant is,

if M16 is less than 292.5 and greater than 247.5 then it is SW.

Answer 1

[Stephen23]

MATLAB is not Excel, and it is better to write code specifically for MATLAB:

>> C = {'N','NE','E','SE','S','SW','W','NW'};
>> fun = @(a) C{1+fix(mod(a+360/16,360)/45)};
>> fun(0)
ans = N
>> fun(-22)
ans = N
>> fun(-90)
ans = W
>> fun(90)
ans = E
>> fun(60)
ans = NE

PS: your code does not work because you invented this syntax:

M16<292.5>247.5

i.e.

A<B>C

which is equivalent to:

(A<B)>C

Because A<B returns either 0 or 1, this is equivalent to either of these:

(1)>C
(0)>C

and this will always be false for any C>=1 (e.g. all of the values that you used).

Rather than inventing syntaxes that do not work, it is more effective to read the MATLAB documentation:

https://www.mathworks.com/help/matlab/relational-operators.html

[Mohana]

Thanks for your kind reply, can this code be used for n values, reading the input from an input file, rather than feeding every time the input value.

[Stephen23]

@Mohana: you can vectorize the code I gave you simply by returning a cell array instead of extracting the cell array contents:

C(1+fix(mod(a+360/16,360)/45));
 ^                           ^ return a cell array

This will also work with a string array.

Answer 2

[Mohana]

Thanks will take care.