FileIO::AsciiRasterInterface Class Reference

Detailed Description

Interface for reading and writing a number of ASCII raster formats. Currently supported are reading and writing of Esri asc-files and reading of Surfer grd-files.

Definition at line 29 of file AsciiRasterInterface.h.

#include <AsciiRasterInterface.h>

Static Public Member Functions
static GeoLib::Raster *	readRaster (std::string const &fname)
static GeoLib::Raster *	getRasterFromASCFile (std::string const &fname)
	Reads an ArcGis ASC raster file.
static GeoLib::Raster *	getRasterFromSurferFile (std::string const &fname)
	Reads a Surfer GRD raster file.
static GeoLib::Raster *	getRasterFromXyzFile (std::string const &fname)
	Reads a XYZ raster file.
static void	writeRasterAsASC (GeoLib::Raster const &raster, std::string const &file_name)
	Writes an Esri asc-file.

Member Function Documentation

getRasterFromASCFile()

GeoLib::Raster * FileIO::AsciiRasterInterface::getRasterFromASCFile ( std::string const & fname )

static

Reads an ArcGis ASC raster file.

Definition at line 131 of file AsciiRasterInterface.cpp.

{
    std::ifstream in(fname.c_str());
 
    if (!in.is_open())
    {
        WARN("Raster::getRasterFromASCFile(): Could not open file {:s}.",
             fname);
        return nullptr;
    }
 
    auto const header = readASCHeader(in);
    if (!header)
    {
        WARN(
            "Raster::getRasterFromASCFile(): Could not read header of file "
            "{:s}",
            fname);
        return nullptr;
    }
 
    std::vector<double> values(header->n_cols * header->n_rows);
    // read the data into the double-array
    for (std::size_t j(0); j < header->n_rows; ++j)
    {
        const std::size_t idx((header->n_rows - j - 1) * header->n_cols);
        for (std::size_t i(0); i < header->n_cols; ++i)
        {
            values[idx + i] = readDoubleFromStream(in);
        }
    }
 
    return new GeoLib::Raster(*header, values.begin(), values.end());
}

References FileIO::readASCHeader(), FileIO::readDoubleFromStream(), and WARN().

Referenced by VtkRaster::loadImage(), main(), MainWindow::mapGeometry(), and readRaster().

getRasterFromSurferFile()

GeoLib::Raster * FileIO::AsciiRasterInterface::getRasterFromSurferFile ( std::string const & fname )

static

Reads a Surfer GRD raster file.

Definition at line 210 of file AsciiRasterInterface.cpp.

{
    std::ifstream in(fname.c_str());
 
    if (!in.is_open())
    {
        ERR("Raster::getRasterFromSurferFile() - Could not open file {:s}",
            fname);
        return nullptr;
    }
 
    auto const optional_header = readSurferHeader(in);
    if (!optional_header)
    {
        ERR("Raster::getRasterFromASCFile() - could not read header of file "
            "{:s}",
            fname);
        return nullptr;
    }
 
    auto const [header, min, max] = *optional_header;
    std::vector<double> values(header.n_cols * header.n_rows);
    // read the data into the double-array
    for (std::size_t j(0); j < header.n_rows; ++j)
    {
        const std::size_t idx(j * header.n_cols);
        for (std::size_t i(0); i < header.n_cols; ++i)
        {
            const double val = readDoubleFromStream(in);
            values[idx + i] = (val > max || val < min) ? header.no_data : val;
        }
    }
 
    return new GeoLib::Raster(header, values.begin(), values.end());
}

References ERR(), FileIO::readDoubleFromStream(), and FileIO::readSurferHeader().

Referenced by VtkRaster::loadImage(), and readRaster().

getRasterFromXyzFile()

GeoLib::Raster * FileIO::AsciiRasterInterface::getRasterFromXyzFile ( std::string const & fname )

static

Reads a XYZ raster file.

Definition at line 260 of file AsciiRasterInterface.cpp.

{
    std::ifstream in(fname.c_str());
    if (!in.is_open())
    {
        ERR("Raster::getRasterFromXyzFile() - Could not open file {:s}", fname);
        return nullptr;
    }
 
    auto coords = readCoordinates(in);
    if (coords == std::nullopt)
    {
        return nullptr;
    }
 
    std::vector<double> values;
    values.push_back((*coords)[2]);
 
    auto coords2 = readCoordinates(in);
    if (coords2 == std::nullopt)
    {
        return nullptr;
    }
    values.push_back((*coords2)[2]);
    GeoLib::RasterHeader header{
        0, 0, 1, GeoLib::Point(*coords), (*coords2)[0] - (*coords)[0], -9999};
 
    std::size_t n_cols = 2, n_rows = 1;
    while ((coords = readCoordinates(in)))
    {
        values.push_back((*coords)[2]);
        if ((*coords)[0] > (*coords2)[0])
        {
            if ((*coords)[0] - (*coords2)[0] != header.cell_size)
            {
                ERR("Varying cell sizes or unordered pixel values found. "
                    "Aborting...");
                return nullptr;
            }
            n_cols++;
        }
        else  // new line
        {
            if ((*coords)[1] - (*coords2)[1] != header.cell_size)
            {
                ERR("Varying cell sizes or unordered pixel values found. "
                    "Aborting...");
                return nullptr;
            }
            n_rows++;
            // define #columns
            if (header.n_cols == 0)
            {
                header.n_cols = n_cols;
            }
            // just check if #columns is consistent
            else
            {
                if (n_cols != header.n_cols)
                {
                    ERR("Different number of pixels per line. Aborting!");
                    return nullptr;
                }
            }
            n_cols = 1;
        }
        coords2 = coords;
    }
    header.n_rows = n_rows;
    if (header.n_cols == 0)
    {
        ERR("Could not determine raster size. Note that minimum allowed raster "
            "size is 2 x 2 pixels.");
        return nullptr;
    }
    return new GeoLib::Raster(header, values.begin(), values.end());
}

References ERR(), and FileIO::readCoordinates().

Referenced by VtkRaster::loadImage(), and readRaster().

readRaster()

GeoLib::Raster * FileIO::AsciiRasterInterface::readRaster ( std::string const & fname )

static

Reads raster file by detecting type based on extension and then calling the appropriate method

Definition at line 26 of file AsciiRasterInterface.cpp.

{
    std::string ext(BaseLib::getFileExtension(fname));
    std::transform(ext.begin(), ext.end(), ext.begin(), tolower);
    if (ext == ".asc")
    {
        return getRasterFromASCFile(fname);
    }
    if (ext == ".grd")
    {
        return getRasterFromSurferFile(fname);
    }
    if (ext == ".xyz")
    {
        return getRasterFromXyzFile(fname);
    }
    return nullptr;
}

References BaseLib::getFileExtension(), getRasterFromASCFile(), getRasterFromSurferFile(), and getRasterFromXyzFile().

Referenced by DirectConditionGenerator::directToSurfaceNodes(), DirectConditionGenerator::directWithSurfaceIntegration(), main(), MeshView::openMap2dMeshDialog(), MeshView::openRasterDataToMeshDialog(), and anonymous_namespace{NetCDFRasterReader.cpp}::readRasterFromFile().

writeRasterAsASC()

void FileIO::AsciiRasterInterface::writeRasterAsASC ( GeoLib::Raster const & raster, std::string const & file_name )

static

Writes an Esri asc-file.

Definition at line 339 of file AsciiRasterInterface.cpp.

{
    GeoLib::RasterHeader header(raster.getHeader());
    MathLib::Point3d const& origin(header.origin);
    unsigned const nCols(header.n_cols);
    unsigned const nRows(header.n_rows);
 
    // write header
    std::ofstream out(file_name);
    out << "ncols " << nCols << "\n";
    out << "nrows " << nRows << "\n";
    auto const default_precision = out.precision();
    out.precision(std::numeric_limits<double>::digits10);
    out << "xllcorner " << origin[0] << "\n";
    out << "yllcorner " << origin[1] << "\n";
    out << "cellsize " << header.cell_size << "\n";
    out.precision(default_precision);
    out << "NODATA_value " << header.no_data << "\n";
 
    // write data
    for (unsigned row(0); row < nRows; ++row)
    {
        for (unsigned col(0); col < nCols - 1; ++col)
        {
            out << raster.data()[(nRows - row - 1) * nCols + col] << " ";
        }
        out << raster.data()[(nRows - row) * nCols - 1] << "\n";
    }
    out.close();
}

References GeoLib::RasterHeader::cell_size, GeoLib::Raster::data(), GeoLib::Raster::getHeader(), GeoLib::RasterHeader::n_cols, GeoLib::RasterHeader::n_rows, GeoLib::RasterHeader::no_data, and GeoLib::RasterHeader::origin.

Referenced by convert(), main(), and VtkVisImageItem::writeAsRaster().

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The documentation for this class was generated from the following files:

• GeoLib/IO/AsciiRasterInterface.h
• GeoLib/IO/AsciiRasterInterface.cpp