Changes

2nd: Array 1 will set the values in its first row to the values in Array 2's 1st column and 1st index.

o2xxx oxxxx

3rd: Finally Array 1 will calculate its 2nd column by performing a calculation on 2 columns in Array 2 which will be represented by the Thread Identifier as the X dimension and the Y dimension being represented by the for loop iterator

__global__ void Calculate (float* u, float* un,int nx, int c, float dx, float dt)