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POParsing and nested pointers
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copied!<p>I am trying to write a program that reads a file containing tetrahedrons formatted as such:</p> <pre><code> T 109 20 10 19 [T X1 X2 X3 X4 ] T 123 34 24 33 T 182 83 82 92 </code></pre> <p>Where each number X in each row denotes a triplet (of x, y and z coordinates) at line X of a data file :</p> <pre><code>line 1 x y z line 2 x y z [.......] line n x y z </code></pre> <p>I have posted a similar (but simpler) question here <a href="https://stackoverflow.com/questions/14729035/parsing-data-from-ascii-formated-file-in-c">Parsing data from ASCII formatted file in C</a> . This time round my idea is to read the tetrahedron file, and store the 4 line numbers representing the coordinates of the vertices of these tetrahedrons in an array <code>vertid[]</code> (0 through 3) and then linking the tetrahedrons to the vertices using an array of pointers to the <code>Vertex</code> structure. I'll summarise: Store line ID numbers in tetrahedron structure and then set pointers to "point" at the correct Vertex. </p> <p>Please bear in mind that I am no programmer (I need this to generate a Voronoi diagram). Also would it be simpler if instead of storing the vertices that makeup the tetrahedrons, I stored the edges (as I believe I will actually require edge data rather than vertex data for the generation of the Voronoi D) ? I have spent my Sunday working on this and its not working and I haven't got a clue why. Thank you.</p> <p>(not working) example:</p> <pre><code>#define FILEPATHtri "/pathto/grid1DT.txt" #define FILEPATHorg "/pathto/grid1.txt" #define MAX 10000 #include <assert.h> #include <stdio.h> #include <stdlib.h> #include "math.h" typedef struct { float x; float y; float z; char ID; }Vertex; /* NOT USED ATM typedef struct { edge_ref next[4]; // pointers to other edges (AQE data structure) void *data[4]; // pointers to endpoints of edge unsigned ID; // ID of edge }Edge; */ typedef struct { Vertex *vert[4]; int vertid[4]; char t; }Tetra; void file_link (void) { Vertex *vert_dt = malloc( MAX * sizeof (Vertex) ) ; Vertex *vert_std = malloc( MAX * sizeof (Vertex) ) ; Tetra *tetrahedron = malloc(MAX * sizeof (Tetra) ); FILE *fp1,*fp2 ; fp1 = fopen( FILEPATHtri,"r"); int i = 0; while(fscanf(fp1, "%c %i %i %i %i ", &tetrahedron[i].t, &tetrahedron[i].vertid[0], &tetrahedron[i].vertid[1], &tetrahedron[i].vertid[2], &tetrahedron[i].vertid[3] ) == 5 ) // Saving the line numbers into vertid[0..3] { i++; } fclose(fp1); fp2 = fopen( FILEPATHorg,"r"); int j = 0; while(fscanf(fp2, "%f %f %f ", &vert_std[j].x, &vert_std[j].y, &vert_std[j].z ) == 3 ) { j++; } fclose(fp2); int n; for (n=0; n<i; n++) { tetrahedron[n]->vert[0]=vert_std[ tetrahedron[n].vertid[0] ]; // retriving coords from the standard file and storing tetrahedron[n]->vert[1]=vert_std[ tetrahedron[n].vertid[1] ]; // them in the vertex pointer array of tretrahedron tetrahedron[n]->vert[2]=vert_std[ tetrahedron[n].vertid[2] ]; tetrahedron[n]->vert[3]=vert_std[ tetrahedron[n].vertid[3] ]; } int m = 100; //used to retrieve m'th tetra, so that I can print the tetra that I want,just for checking purposes.. // printing 13 variables in total... printf("These are the 4 coordinates of the vertices of the %i th tetrahedron from the DT file %f %f %f\n%f %f %f\n%f %f %f\n%f %f %f\n", n, tetrahedron[n]->vert[0]->x,tetrahedron[n]->vert[0]->y,tetrahedron[n]->vert[0]->z, tetrahedron[n]->vert[1]->x,tetrahedron[n]->vert[1]->y,tetrahedron[n]->vert[1]->z, tetrahedron[n]->vert[2]->x,tetrahedron[n]->vert[2]->y,tetrahedron[n]->vert[2]->z, tetrahedron[n]->vert[3]->x,tetrahedron[n]->vert[3]->y,tetrahedron[n]->vert[3]->z); free(vert_dt); free(vert_std); free(tetrahedron); } int main(void) { file_link(); return 0; } </code></pre>

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