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SurfaceOfEarth grid program help needed
Would anyone know how to write this, or have a few pointers to get me started on this program...it's the last program I need to write & I have no clue how to.
If we ignore plate tectonics, we can model changes in the surface of the Earth as becoming flatter due to wind and water erosion. Given a terrain dataset from the present, we should be able simulate this flattening process over time. Assume that terrain data is read from a file and stored in a two dimensional array. The first line of the data file also provides an integer value for
the number of rows and an integer value for the number of columns of the area. The elevationvalues in subsequent lines are of type double. Given the current grid position grid[m][n],
after one million years, the altitude of this grid position could be projected to be the average of all the adjacent grid positions including itself. In other words, the new grid value will become:
new_grid[m][n] = ( grid[m-1][n-1] + grid[m-1][n] + grid[m-1][n+1]
+ grid[m][n-1] + grid[m][n] + grid[m][n+1]
+ grid[m+1][n-1] + grid[m+1][n] + grid[m+1][n+1]) /9
However, due to inhomogeneities in wind and water erosion, the altitude of the new grid may fluctuate by as much as 20%, which means
0.8*new_grid[m][n] <= new_grid_real[m][n] <= 1.2*new_grid[m][n]
The position new_grid_real[m][n] should be uniformly distributed between the upper and lower bound. Hint: This effect could be simulated by a random function.
Write a program to read in a grid data set, simulate the flattening process and generate a file containing the new grid. The input to your program should be a file called “CurrentSurface.dat”.
The output file should be named “FutureSurface.dat”. You may assume that the grid will not exceed 500 rows by 500 columns.
Tip1: If a grid element is on the outside border (in other words is does not have neighbors on all sides), then you will only need to consider those neighboring grid elements with valid indices.
For example consider the element grid[0][1]:
new_grid[0][1] = ( grid[-1][0] + grid[-1][1] + grid[-1][2]
+ grid[0][0] + grid[0][1] + grid[0][2]
+ grid[1][0] + grid[1][1] + grid[1][2]) / 9
However there is no row -1. Consequently, this grid element has only 5 neighbors. So the computation to compute the new element includes those 5 neighbors and the element itself:
new_grid[0][1] = ( grid[0][0] + grid[0][1] + grid[0][2]
+ grid[1][0] + grid[1][1] + grid[1][2]) / 6
Notice that the total number of elements in the computation is now 6 instead of 9.
You might consider using if-statements to handle out-of-range indices. Keep in mind that since
the array describes a rectangle, there are border elements on all four sides.
If we ignore plate tectonics, we can model changes in the surface of the Earth as becoming flatter due to wind and water erosion. Given a terrain dataset from the present, we should be able simulate this flattening process over time. Assume that terrain data is read from a file and stored in a two dimensional array. The first line of the data file also provides an integer value for
the number of rows and an integer value for the number of columns of the area. The elevationvalues in subsequent lines are of type double. Given the current grid position grid[m][n],
after one million years, the altitude of this grid position could be projected to be the average of all the adjacent grid positions including itself. In other words, the new grid value will become:
new_grid[m][n] = ( grid[m-1][n-1] + grid[m-1][n] + grid[m-1][n+1]
+ grid[m][n-1] + grid[m][n] + grid[m][n+1]
+ grid[m+1][n-1] + grid[m+1][n] + grid[m+1][n+1]) /9
However, due to inhomogeneities in wind and water erosion, the altitude of the new grid may fluctuate by as much as 20%, which means
0.8*new_grid[m][n] <= new_grid_real[m][n] <= 1.2*new_grid[m][n]
The position new_grid_real[m][n] should be uniformly distributed between the upper and lower bound. Hint: This effect could be simulated by a random function.
Write a program to read in a grid data set, simulate the flattening process and generate a file containing the new grid. The input to your program should be a file called “CurrentSurface.dat”.
The output file should be named “FutureSurface.dat”. You may assume that the grid will not exceed 500 rows by 500 columns.
Tip1: If a grid element is on the outside border (in other words is does not have neighbors on all sides), then you will only need to consider those neighboring grid elements with valid indices.
For example consider the element grid[0][1]:
new_grid[0][1] = ( grid[-1][0] + grid[-1][1] + grid[-1][2]
+ grid[0][0] + grid[0][1] + grid[0][2]
+ grid[1][0] + grid[1][1] + grid[1][2]) / 9
However there is no row -1. Consequently, this grid element has only 5 neighbors. So the computation to compute the new element includes those 5 neighbors and the element itself:
new_grid[0][1] = ( grid[0][0] + grid[0][1] + grid[0][2]
+ grid[1][0] + grid[1][1] + grid[1][2]) / 6
Notice that the total number of elements in the computation is now 6 instead of 9.
You might consider using if-statements to handle out-of-range indices. Keep in mind that since
the array describes a rectangle, there are border elements on all four sides.
no one knows how to do this??? If someone wrote the code I'd be willing to paypal them money
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