Produce an eggbox

Dear all, I should produce an eggbox. I tried to use this code, following the instructions, but I did not receive what I needed. Where's the error?

        x=[-10:0.2469135802469136:+10]
        y=[-10:0.2469135802469136:+10]
        [X,Y]= meshgrid(x,y)
        M1=sin(X)
        M2=sin(Y)
        M12=M1*M2
        surf(X,Y)
        X.^2

Thanks a lot

Answer 1

[bym]

The hint explicitly said element-by-element multiplication which is accomplished via

 M12 = M1.*M2  % note the use of  .*

[Image Analyst]

You forgot to tell him to use surf(M12) instead of surf(X, Y);

Answer 2

[Fangjun Jiang]

Do you mean your last line to be surf(X,Y, X.^2)? It plotted something but I don't know what is an eggbox.

[Orlando]

This is the exercise, and there is also an example of an eggbox.

<http://www.image-upload.net/viewer.php?file=uvu9z4g0endn7vsrubvw.jpg>

<http://www.image-upload.net/viewer.php?file=ommgobtzw9ymdwzo2rq.jpg>

<http://www.image-upload.net/viewer.php?file=i0xmzjlh0hd7yaclqwrz.png>

Thanks a lot

[Fangjun Jiang]

You call the MATLAB logo an egg box? Mr. Little and Mr. Moler will be mad.

Answer 3

[Image Analyst]

Change the last two lines to

          M12 = M1 .* M2
          surf(M12)

[Orlando]

Thanks a lot also to you!