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Feel free to correct the grammar mistakes in my posts.


Jul
22
comment DSolve breaks when the ordering of independent variables aren't proper?
@chris Yeah, v9.0.1 and Wolfram Programming Cloud returned unevaluated after the warning, too.
Jul
22
revised DSolve breaks when the ordering of independent variables aren't proper?
added 25 characters in body
Jul
22
comment Use NDSolve to solve a PDE
@wdg It's bc, I forgot I changed the name, edited, thx for pointing out :)
Jul
22
revised Use NDSolve to solve a PDE
deleted 7 characters in body
Jul
22
answered Use NDSolve to solve a PDE
Jul
22
asked DSolve breaks when the ordering of independent variables aren't proper?
Jul
21
reviewed Approve suggested edit on Covariant derivative for symbolic tensors
Jul
21
answered An easier way to find the properties of an ellipse from its equation?
Jul
21
comment How to define two polyhedron intersect or not?
Well, if you want to call someone who isn't the original poster that appearing in the comment, you need to add @someone in your comment, or others won't see the reminder. RegionIntersection can be used for 3D object, for example d1 = {{0, 0, 0}, {1, 0, 0}, {0, 1, 0}, {0, 0, 1}}; d2={{0,0,0},{1/2,1/2,1/2},{1,0,0},{1,1,0}};r=RegionIntersection@@(Tetrahedron/@{‌​d1,d2});RegionMember[r,{x,y,z}]//Reduce
Jul
19
reviewed Reject suggested edit on Deleting all characters in a string that do not belong to a small set of elements
Jul
19
reviewed Approve suggested edit on Solve matrix equation A*X=X*B using LeastSquares
Jul
19
comment How to define two polyhedron intersect or not?
Well, as @Nasser mentioned above, it's not so proper to ask question 2 here. (It's a little too board. ) As to the 1st question, have you looked into Simplex, RegionIntersection, RegionMember in v10?
Jul
19
comment How to define two polyhedron intersect or not?
OK, then what's the meaning of "When the concrete aggregate become more and more in a cubic region, it is very difficult to add new aggregate in the region, How can deal with this problem"?
Jul
19
comment How to define two polyhedron intersect or not?
It'll be good if you can check your code before pasting it here, now, where's the definition of IntersectofTwoTriangles? Still, you didn't explain the meaning of your question 2.
Jul
19
comment How to define two polyhedron intersect or not?
Your code is incomplete, where's the definition of PointInandOnorOut3DTriangle? Also, I think IntersectofLineTriangle isn't a function that "decide if 2 polyhedrons are intersecting".
Jul
19
comment How to define two polyhedron intersect or not?
Please have a look at this and format your code just as @jtbandes did for you.
Jul
19
comment How to define two polyhedron intersect or not?
For the first question, do you mean "how to decide if 2 polyhedrons are intersecting"? Then, I can't understand your second question very well.
Jul
18
revised How to speed up recursive compiled functions?
added 418 characters in body
Jul
18
answered How to speed up recursive compiled functions?
Jul
18
comment Factoring a differential equation into an operator product
If you just want to get $r_1, r_2,\cdots,r_n$ you can simply Solve $ a_n x^n + a_{n-1} x^{n-1} +\cdots+a_1 x+a_0 = 0 $.