getting wrong values when coding

Question

Guan-Yu 2014-10-2

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/157060-getting-wrong-values-when-coding

回答： Mischa Kim 2014-10-2

Hello,

    There may be something wrong of my code that the outcome seems peculiar.
    Here is my code.

>> [x,y]=meshgrid(0:0.02:1,0:1:0);

>> u=0*x;

>> v=4*(1*x-(x.^2));

>> quiver(x,y,u,v);

    I just want to do vector analysis, and the outcome of v is the same as my expectation; that is,

v =

Columns 1 through 14
         0    0.0784    0.1536    0.2256    0.2944    0.3600    0.4224    0.4816    0.5376    0.5904    0.6400    0.6864    0.7296    0.7696
Columns 15 through 28
    0.8064    0.8400    0.8704    0.8976    0.9216    0.9424    0.9600    0.9744    0.9856    0.9936    0.9984    _1.0000_    0.9984    0.9936
Columns 29 through 42
    0.9856    0.9744    0.9600    0.9424    0.9216    0.8976    0.8704    0.8400    0.8064    0.7696    0.7296    0.6864    0.6400    0.5904
Columns 43 through 51
    0.5376    0.4816    0.4224    0.3600    0.2944    0.2256    0.1536    0.0784         0
======================================================================================
    The maximum of v is obviously one. But after graphing(quiver function), it doesn't equal to one. And I just want to know which part of my code is wrong.