@tomleslie 

The style of the mesh of the following plot looks attractive to me. Is this possible on maple?

@tomleslie thanks for your interest.

All right, could you help me for writing if statements?

I am agree with you Mr. @Carl Love.

@tomleslie, your code is good. but how do we guarentee that 0<z[i,j]<1 ? 

@acer Thanks.
I read to help about PDEplots.
 

But I can't accomplish to use it. In this question, what will we write instead of inits (initial data)?