Same values's aswer in MATLAB Grader but identified as a mistake.

Question

adam soker 2022-4-1

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1686389-same-values-s-aswer-in-matlab-grader-but-identified-as-a-mistake

编辑： Cris LaPierre 2022-4-4

The references solution for 'f' is:

a = 4 
m = 3 
b = -3 
l = 6 
C1 = -0.42 
C2 = -4.00 
C3 = -2.07 
C4 = 0.30
t = -10:0.1:10;
s = t.*(t>=0 & t<=1);
sa = (t-a).*((t-a)>=0 & (t-a)<=1);
sm = m.*s;
sb = (t/b).*((t/b)>=0 & (t/b)<=1);
sdr = (l-t).*((l-t)>=0 & (l-t)<=1);
f = C1*sa + C2*sm + C3*sb + C4*sdr;

The student's solution is:

f = ((-0.42)*t+1.68).*(t>=4 & t<=5)-12*t.*(t>=0 & t<=1) + (0.69)*t.*(t<=0 & t>=(-3))+(1.8-0.3*t).*(t<=6 & t>=5);

The solutions should be the same. But when them there is a size 1.6653e-16 error, so the student's answer is not accepted.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Cris LaPierre 2022-4-1

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1686389-same-values-s-aswer-in-matlab-grader-but-identified-as-a-mistake#answer_932264

编辑：Cris LaPierre 2022-4-4

How have you set up your assessment test? Are you using the Variable Equals Reference Solution test or a MATLAB Code test type? If MATLAB Code, have you incorporated tolerances into your equality check?

When I test the code you have shared in Grader, the learner solution's value of f is marked correct.

I used the drop down test "Variable equals reference solution" and entered f as the "variable name you want to compare". This automatically applies a +/- 0.1% relative or +/- 0.0001 absolute tolerance to the solution. This means a difference of 1.6653e-16 is considered equal.