How to assign a variable using 3 arrays in C #
I am trying to write an add-on for a finite element software snippet.
I have three arrays which are essentially a coordinate system. I want to assign a value to a variable based on its position in the grid. Basically what I want to say is that if my node is within the x range and the y range, then my aquifer thickness at that node is equal to that value. As long as I have it.
//create an array of xcoords of data points:
double[] xcoord = new double[11] {0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50};
//create an array of ycoords of data points:
double[] ycoord = new double[11] {0, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50};
//create an array of aquifer thickness
double[] aquiferThicknessPoints = new double[121]
{
10, 10, 12, 13, 12, 15, 14, 15, 14, 13, 13,
10, 10, 13, 15, 16, 14, 13, 15, 16, 12, 13,
12, 14, 15, 18, 19, 17, 14, 15, 18, 14, 14,
13, 14, 15, 18, 20, 17, 15, 17, 18, 15, 15,
14, 15, 17, 18, 21, 17, 18, 18, 19, 17, 16,
15, 15, 17, 17, 20, 21, 21, 19, 19, 18, 18,
15, 15, 17, 20, 20, 21, 22, 21, 19, 19, 19,
16, 17, 19, 20, 22, 23, 22, 21, 20, 20, 20,
17, 18, 20, 22, 23, 24, 24, 23, 22, 20, 21,
18, 19, 21, 22, 24, 25, 24, 23, 22, 22, 22,
19, 19, 22, 22, 24, 25, 25, 23, 23, 22, 23,
};
dataPointSpacingHalf = dataPointSpacing / 2;
for (int i = 0; i < xcoord.Length; i++)
{
for (int j = 0; j < ycoord.Length; j++)
{
if (nodeX >= (xcoord[i] - dataPointSpacingHalf) && (nodeX < (xcoord[i] + dataPointSpacingHalf)) && (nodeY >= (ycoord[j] - dataPointSpacingHalf) && (nodeY < (ycoord[j] + dataPointSpacingHalf))))
{
aquiferThickness = aquiferThicknessPoints[?];
}
}
}
I can see the loops of the nested loops going through 110 times, but I have no idea how to assign the thickness of the aquifer from my array to each loop.
I am discovering any way to solve this problem as I am very new to programming and I am still not sure if this is the best way to achieve something.
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Just use i * xcoord.Length + j
insted?
Here is the code:
for (int i = 0; i < xcoord.Length; i++)
{
for (int j = 0; j < ycoord.Length; j++)
{
//Here is the magic!
//without considering coordinates
//aquiferThickness[i, j] = aquiferThicknessPoints[i * xcoord.Length + j];
//considering coordinates
aquiferThickness[i, j] =
aquiferThicknessPoints[
CoordToIndex(xNode,indexedCoords) * xcoord.Length +
CoordToIndex(yNode,indexedCoords)];
}
}
Also to consider the xNode, yNode coordinate you can use this approach
Dictionary<int, double> indexedCoords = new Dictionary<int, double> { { 0, 0 }, { 1, 5 }, { 2, 10 }, .... };
int CoordToIndex(double node, Dictionary<int, double> indexedCoords)
{
return indexedCoords.First(i => i.Value > node).Key;
}
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You want to use a two dimensional array for aquiferThicknessPoints
:
double[,] aquiferThicknessPoints = new double[,]
{
{10, 10, 12, 13, 12, 15, 14, 15, 14, 13, 13},
{10, 10, 13, 15, 16, 14, 13, 15, 16, 12, 13},
{12, 14, 15, 18, 19, 17, 14, 15, 18, 14, 14},
{13, 14, 15, 18, 20, 17, 15, 17, 18, 15, 15},
// the rest
};
Then you can address the data using two coordinates:
aquiferThickness = aquiferThicknessPoints[j, i];
(or i, j
, it's not clear how your data is organized)
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