/**
@brief Reads an ArcGrid ASCII file
@author Richard Barnes
@param[in] &filename Name of ArcGrid ASCII file to read
@param[out] &elevations DEM object containing contents of file
@returns 0 upon success
*/
int load_ascii_data(const char filename[], float_2d &elevations){
FILE *fin;
long long file_size;
int rows,columns;
Timer load_time;
ProgressBar progress;
load_time.start();
errno=0;
diagnostic_arg("Opening input ASCII-DEM file \"%s\"...",filename);
fin=fopen(filename,"r");
if(fin==NULL){
diagnostic_arg("failed with error %d: \"%s\"!\n",errno,strerror(errno));
exit(-1);
}
diagnostic("succeeded.\n");
diagnostic("Calculating file size...");
if(fseek(fin,-1,SEEK_END)!=0){
diagnostic("failed! (Couldn't jump to end of file.)\n");
exit(-1);
}
if((file_size=ftell(fin))==-1){
diagnostic("failed! (Couldn't determine file size.)\n");
exit(-1);
}
if(fseek(fin,0,SEEK_SET)!=0){
diagnostic("failed! (Couldn't jump back to beginning of file.)\n");
exit(-1);
}
diagnostic("succeeded.\n");
// posix_fadvise(fileno(fin),0,0,POSIX_FADV_SEQUENTIAL);
diagnostic("Reading DEM header...");
if(fscanf(fin,"ncols %d nrows %d xllcorner %lf yllcorner %lf cellsize %lf NODATA_value %f",&columns, &rows, &elevations.xllcorner, &elevations.yllcorner, &elevations.cellsize, &elevations.no_data)!=6){
diagnostic("failed!\n");
exit(-1);
}
diagnostic("succeeded.\n");
diagnostic_arg("The loaded DEM will require approximately %ldMB of RAM.\n",columns*rows*((long)sizeof(float))/1024/1024);
diagnostic("Resizing elevation matrix..."); //TODO: Consider abstracting this block
elevations.resize(columns,rows);
diagnostic("succeeded.\n");
diagnostic("%%Reading elevation matrix...\n");
progress.start(file_size);
float temp;
elevations.data_cells=0;
for(int y=0;y<rows;y++){
progress.update(ftell(fin)); //Todo: Check to see if ftell fails here?
for(int x=0;x<columns;x++){
if (fscanf(fin,"%f", &temp)!=1){
diagnostic("\n\tFailed! (Couldn't read or convert a value!)\n");
exit(-1);
}
elevations(x,y)=temp;
if(temp!=elevations.no_data)
elevations.data_cells++;
}
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
fclose(fin);
diagnostic_arg(
"Read %ld cells, of which %ld contained data (%ld%%).\n",
elevations.width()*elevations.height(), elevations.data_cells,
elevations.data_cells*100/elevations.width()/elevations.height()
);
load_time.stop();
diagnostic_arg("Read time was: %lfs\n", load_time.accumulated());
return 0;
}
void dinf_upslope_area_interval(const float_2d &flowdirs, grid_engine< boost::numeric::interval<T> > &area){
char_2d dependency;
std::queue<grid_cell> sources;
ProgressBar progress;
diagnostic_arg("The sources queue will require at most approximately %ldMB of RAM.\n",flowdirs.width()*flowdirs.height()*((long)sizeof(grid_cell))/1024/1024);
diagnostic("Setting up the dependency matrix...");
dependency.copyprops(flowdirs);
dependency.init(0);
diagnostic("succeeded.\n");
diagnostic("Setting up the area matrix...");
area.copyprops(flowdirs);
area.init((float)0);
area.no_data=dinf_NO_DATA;
diagnostic("succeeded.\n");
bool has_cells_without_flow_directions=false;
diagnostic("%%Calculating dependency matrix & setting no_data cells...\n");
progress.start( flowdirs.width()*flowdirs.height() );
#pragma omp parallel for reduction(|:has_cells_without_flow_directions)
for(int x=0;x<flowdirs.width();x++){
progress.update( x*flowdirs.height() );
for(int y=0;y<flowdirs.height();y++){
if(flowdirs(x,y)==flowdirs.no_data){
area(x,y)=area.no_data;
dependency(x,y)=9; //Note: This is an unnecessary safety precaution
continue;
}
if(flowdirs(x,y)==NO_FLOW){
has_cells_without_flow_directions=true;
continue;
}
int n_high,n_low;
int nhx,nhy,nlx,nly;
where_do_i_flow(flowdirs(x,y),n_high,n_low);
nhx=x+dinf_dx[n_high],nhy=y+dinf_dy[n_high];
if(n_low!=-1){
nlx=x+dinf_dx[n_low];
nly=y+dinf_dy[n_low];
}
if( n_low!=-1 && flowdirs.in_grid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.no_data )
dependency(nlx,nly)++;
if( flowdirs.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data )
dependency(nhx,nhy)++;
}
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
if(has_cells_without_flow_directions)
diagnostic("\033[91mNot all cells had defined flow directions! This implies that there will be digital dams!\033[39m\n");
diagnostic("%%Locating source cells...\n");
progress.start( flowdirs.width()*flowdirs.height() );
for(int x=0;x<flowdirs.width();x++){
progress.update( x*flowdirs.height() );
for(int y=0;y<flowdirs.height();y++)
if(flowdirs(x,y)==flowdirs.no_data)
continue;
else if(flowdirs(x,y)==NO_FLOW)
continue;
else if(dependency(x,y)==0)
sources.push(grid_cell(x,y));
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
diagnostic("%%Calculating up-slope areas...\n");
progress.start( flowdirs.data_cells );
long int ccount=0;
while(sources.size()>0){
grid_cell c=sources.front();
sources.pop();
ccount++;
progress.update(ccount);
if(flowdirs(c.x,c.y)==flowdirs.no_data) //TODO: This line shouldn't be necessary since NoData's do not get added below
continue;
area(c.x,c.y)+=1;
if(flowdirs(c.x,c.y)==NO_FLOW)
continue;
int n_high,n_low,nhx,nhy,nlx,nly;
where_do_i_flow(flowdirs(c.x,c.y),n_high,n_low);
nhx=c.x+dinf_dx[n_high],nhy=c.y+dinf_dy[n_high];
float phigh,plow;
area_proportion(flowdirs(c.x,c.y), n_high, n_low, phigh, plow);
if(flowdirs.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data)
area(nhx,nhy)+=area(c.x,c.y)*(T)phigh;
if(n_low!=-1){
nlx=c.x+dinf_dx[n_low];
nly=c.y+dinf_dy[n_low];
if(flowdirs.in_grid(nlx,nly) && flowdirs(nlx,nly)!=flowdirs.no_data){
area(nlx,nly)+=area(c.x,c.y)*(T)plow;
if((--dependency(nlx,nly))==0)
sources.push(grid_cell(nlx,nly));
}
}
if( flowdirs.in_grid(nhx,nhy) && flowdirs(nhx,nhy)!=flowdirs.no_data && (--dependency(nhx,nhy))==0)
sources.push(grid_cell(nhx,nhy));
}
diagnostic_arg(SUCCEEDED_IN,progress.stop());
}
