Added fortran version of md example (not working fully yet). Added an example for getting positions from file. Minor fixes.

1 files changed, 97 insertions, 0 deletions

diff --git a/src/tests/tng_io_read_pos.c b/src/tests/tng_io_read_pos.c
new file mode 100644
index 0000000..4ab27da
--- /dev/null
+++ b/src/tests/tng_io_read_pos.c
@@ -0,0 +1,97 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <tng_io.h>
+
+int main(int argc, char **argv)
+{
+    tng_trajectory_t traj;
+    union data_values ***positions = 0; // A 3-dimensional array to be populated
+    int64_t n_particles, n_values_per_frame, n_frames;
+    tng_data_type data_type;
+    int i, j;
+    int64_t particle = 0;
+    // Set a default frame range
+    int first_frame = 0, last_frame = 50;
+
+    if(argc <= 1)
+    {
+        printf("No file specified\n");
+        printf("Usage:\n");
+        printf("tng_io_read_pos <tng_file> [particle number = %"PRId64"] "
+               "[first_frame = %d] [last_frame = %d]\n",
+               particle, first_frame, last_frame);
+        exit(1);
+    }
+
+    // A reference must be passed to allocate memory
+    if(tng_trajectory_init(&traj) != TNG_SUCCESS)
+    {
+        tng_trajectory_destroy(&traj);
+        exit(1);
+    }
+    tng_input_file_set(traj, argv[1]);
+
+    // Read the file headers
+    tng_file_headers_read(traj, TNG_USE_HASH);
+
+    if(argc >= 3)
+    {
+        particle = strtoll(argv[2], 0, 10);
+        if(argc >= 4)
+        {
+            first_frame = strtoll(argv[3], 0, 10);
+            if(argc >= 5)
+            {
+                last_frame = strtoll(argv[4], 0, 10);
+            }
+        }
+    }
+
+    n_frames = last_frame - first_frame + 1;
+
+    // Get the positions of all particles in the requested frame range.
+    // The positions are stored in the positions array.
+    // N.B. No proper error checks.
+    if(tng_particle_data_interval_get(traj, TNG_TRAJ_POSITIONS, first_frame,
+       last_frame, TNG_USE_HASH, &positions, &n_particles, &n_values_per_frame,
+       &data_type) != TNG_SUCCESS)
+    {
+        printf("Cannot read positions\n");
+    }
+    else
+    {
+        // Print the positions of the wanted particle (zero based)
+        for(i=first_frame; i<=last_frame; i++)
+        {
+            printf("%d", i);
+            for(j=0; j<n_values_per_frame; j++)
+            {
+                switch(data_type)
+                {
+                case TNG_INT_DATA:
+                    printf("\t%"PRId64"", positions[i][particle][j].i);
+                    break;
+                case TNG_FLOAT_DATA:
+                    printf("\t%f", positions[i][particle][j].f);
+                    break;
+                case TNG_DOUBLE_DATA:
+                    printf("\t%f", positions[i][particle][j].d);
+                    break;
+                default:
+                    break;
+                }
+                printf("\n");
+            }
+        }
+    }
+
+    // Free memory
+    if(positions)
+    {
+        tng_particle_data_values_free(positions, n_frames, n_particles,
+                                      n_values_per_frame, data_type);
+    }
+    tng_trajectory_destroy(&traj);
+
+    return(0);
+}