determine all cells are non-zero within a matrix

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Peng Zhao 2019-7-3

0
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https://ww2.mathworks.cn/matlabcentral/answers/470079-determine-all-cells-are-non-zero-within-a-matrix

评论： Peng Zhao 2019-7-3

I am trying to determine if all of the numbers in "x" is non-zero values:

x = [1 1 0]
% 1:
if x ~= [0 0 0]
    disp('x is not zeros')
end
% 2:
if all(x ~= 0)
    disp('x is not zeros')
end

but the output is saying the x is zeros.

what mistake did I make?

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Peng Zhao 2019-7-3

在 MATLAB Online 中打开

Pref_Color_offset = 0.1;
if all(Pref_Color ~= 0)
    disp('yes')
    for i = 1:1:3
        if Pref_Color(i) >= Pref_Color_offset
            Pref_Color_Darkened(i) = Pref_Color(i) - Pref_Color_offset;
        else
            Pref_Color_Darkened(i) = Pref_Color(i);
        end
        if Pref_Color_Darkened(i) >= (5*Pref_Color_offset)
            Pref_Color_Darkened_More(i) = Pref_Color_Darkened(i) - (5*Pref_Color_offset);
        else
            Pref_Color_Darkened_More(i) = Pref_Color_Darkened(i);
        end
    end
else
    disp('no')
    Pref_Color_Darkened = [0.15 0.15 0.15];
    Pref_Color_Darkened_More = [1 1 1];
end

This is what I have, with a input of: Pref_Color = [1 1 0]

However, I am getting an "no" as the output.

see:

>> Pref_Color = [1 1 0];
>> Pref_Color_offset = 0.1;
if all(Pref_Color ~= 0)
    disp('yes')
    for i = 1:1:3
        if Pref_Color(i) >= Pref_Color_offset
            Pref_Color_Darkened(i) = Pref_Color(i) - Pref_Color_offset;
        else
            Pref_Color_Darkened(i) = Pref_Color(i);
        end
        if Pref_Color_Darkened(i) >= (5*Pref_Color_offset)
            Pref_Color_Darkened_More(i) = Pref_Color_Darkened(i) - (5*Pref_Color_offset);
        else
            Pref_Color_Darkened_More(i) = Pref_Color_Darkened(i);
        end
    end
else
    disp('no')
    Pref_Color_Darkened = [0.15 0.15 0.15];
    Pref_Color_Darkened_More = [1 1 1];
end
no
>> 

Adam 2019-7-3

And why isn't this the expected answer? You are testing if all elements of Pref_Color are not equal to 0. Clearly this is false because the final element is 0 therefore it drops into your else block and reports 'no'.

Peng Zhao 2019-7-3