Calculation of the volume of an irregular plot of land

Question

The code consists of calculating the volume of an uneven surface where I am using a matrix 2 x 2 of maximum size 1000 x 1000, which represents a rectangle, so the maximum area of the land is 1.000.000 m², and I must use a variable y free, which represents the height of the land, as the terrain is irregular the y varies, in areas of slopes and slopes of the land.

I want to calculate the total volume of the land, where I should use an incremental delta applied to the coordinates X, Y and Z. At each step of applying the delta to the coordinates, a calculation/addition of the volume of a small cube of volume delta³ to the total volume of the land, not exceeding the dimensions of the land or the calculation will be wrong, where here also for the coordinate Y, I must calculate a line of interpolation between two heights Y in order to determine the limit of cubes added for the calculation of the volume, that is, a limit for the progression of the loop that will systematically scan the height of the terrain.

When a cube crosses the boundary of the coordinate Y interpolated is the time to end the loop that increments the coordinate Y.

I’m doubtful how to do this I wrote a code, below follows the loop part, however an error occurs and I’m doubtful how to fix:

for(i=0; i<x; i++){ // x representa a largura do terreno
    for(j=0; j<z; j++){ // z representa a profundidade do terreno
        fscanf(y, "%.2f\t", altitude[i][j]); // Armazena os valores das coordenadas x e z na altura y ( DÚVIDA NESSA LINHA, SEMPRE QUE TENTO ARMAZENAR NA VARIÁVEL Y, OCORRE ERRO )
    }
} 

for(i=0; i<x; i++){
    for(j=0; j<z; j++){
        delta = aux - altitude[i][j];
        volume = volume +(altitude[i][j]*delta);
        aux=altitude[i][j];
    }
}

printf("\n O volume do terreno é: %f\n", volume);

Answer 1

I don’t quite understand what you want to do in line with the instruction fscanf, but if you are trying to save the result to a file, it would be best to use the instruction fputs. Take a little look here.

But if you just want to calculate the total volume of the land, you just need to sum up all the heights you stored in the array. Something like this:

// inicializa volume com 0 para acumular no loop
int volume = 0;
for(i=0; i<x; i++){
    for(j=0; j<z; j++){
      // adiciona o volume de cada área
      volume += altitude[i][j];
    }
}

At the end of this loop, the variable volume shall have the total volume of the land.