寻找能够读取HDF4文件格式的.NET库

1

当我工作的这个问题前一段时间，我无法找到任何HDF4为.NET。（我认为这是有道理的，因为HDF4不再受到真正的支持，而HDF4最早是在1995年左右创建的。）

我最终做的是滚动我自己的库来执行非常特定的命令来传送HDF文件。大部分内容不值得分享，但以下内容可能有助于P/Invoke签名（并非所有签名都可能已经过测试等）。

public class HDF4 
{ 
    #region DLL Imports 
    private const string HDF4DLL = "hm421m.dll"; 

    #region file/dataset access 

    [DllImport(HDF4DLL)] 
    public static extern int SDcreate(int sd_id, string name, DataTypeDefinitions data_type, int rank, int[] dimsizes); 

    [DllImport(HDF4DLL)] 
    public static extern int SDstart(string filename, AccessCodes access_mode); 

    [DllImport(HDF4DLL)] 
    public static extern short SDendaccess(int sds_id); 

    [DllImport(HDF4DLL)] 
    public static extern short SDend(int sd_id); 

    #endregion 

    #region data access 

    [DllImport(HDF4DLL)] 
    public static extern int SDselect(int sd_id, int sds_index); 

    [DllImport(HDF4DLL)] 
    public static extern int SDreaddata(int sds_id, int[] start, int[] stride, int[] edge, IntPtr buffer); 

    [DllImport(HDF4DLL)] 
    public static extern int SDwritedata(int sds_id, int[] start, int[] stride, int[] edge, IntPtr buffer); 

    [DllImport(HDF4DLL)] 
    public static extern short SDgetdatastrs(int sds_id, StringBuilder label, StringBuilder unit, StringBuilder format, int length); 

    [DllImport(HDF4DLL)] 
    public static extern short SDsetdatastrs(int sds_id, string label, string unit, string format, string coordsys); 

    #endregion 

    #region dim 

    [DllImport(HDF4DLL)] 
    public static extern int SDgetdimid(int sds_id, int dim_index); 

    [DllImport(HDF4DLL)] 
    public static extern short SDdiminfo(int dim_id, StringBuilder name, out int size, out DataTypeDefinitions datay_type, out int num_attrs); 

    [DllImport(HDF4DLL)] 
    public static extern short SDgetdimstrs(int dim_id, StringBuilder label, StringBuilder unit, StringBuilder format, int length); 

    [DllImport(HDF4DLL)] 
    public static extern short SDgetdimscale(int dim_id, IntPtr data); 

    [DllImport(HDF4DLL)] 
    public static extern short SDsetdimname(int dim_id, string dim_name); 

    [DllImport(HDF4DLL)] 
    public static extern short SDsetdimscale(int dim_id, int count, DataTypeDefinitions data_type, IntPtr data); 

    [DllImport(HDF4DLL)] 
    public static extern short SDsetdimstrs(int dim_id, string label, string unit, string format); 

    #endregion 

    #region lookups/checks 

    [DllImport(HDF4DLL)] 
    public static extern int SDcheckempty(int sds_id, out bool emptySDS); 

    [DllImport(HDF4DLL)] 
    public static extern int SDnametoindex(int sd_id, string sds_name); 

    [DllImport(HDF4DLL)] 
    public static extern int SDfileinfo(int sd_id, out int num_datasets, out int num_global_attrs); 

    [DllImport(HDF4DLL)] 
    public static extern short SDgetinfo(int sds_id, StringBuilder sds_name, out int rank, [In, Out] int[] dimsizes, out DataTypeDefinitions data_type, 
     out int num_attrs); 

    [DllImport(HDF4DLL)] 
    public static extern bool SDiscoordvar(int sds_id); 


    #endregion 

    #region attr 

    [DllImport(HDF4DLL)] 
    public static extern int SDfindattr(int obj_id, string attr_name); 

    [DllImport(HDF4DLL)] 
    public static extern short SDattrinfo(int obj_id, int attr_index, StringBuilder attr_name, out DataTypeDefinitions data_type, out int count); 

    [DllImport(HDF4DLL)] 
    public static extern short SDreadattr(int obj_id, int attr_index, StringBuilder attr_buff); 

    [DllImport(HDF4DLL)] 
    public static extern short SDsetattr(int obj_id, string attr_name, DataTypeDefinitions data_type, int count, StringBuilder values); 

    #endregion 

    #endregion 

    #region Enums/Consts 

    public const uint DFNT_NATIVE = 4096; 
    public const int MAX_VAR_DIMS = 32; 

    [Flags] 
    public enum DataTypeDefinitions : uint 
    { 
     DFNT_CHAR8  = 4, 
     DFNT_CHAR  = 4, 
     DFNT_UCHAR8  = 3, 
     DFNT_UCHAR  = 3, 
     DFNT_INT8  = 20, 
     DFNT_UINT8  = 21, 
     DFNT_INT16  = 22, 
     DFNT_UINT16  = 23, 
     DFNT_INT32  = 24, 
     DFNT_UINT32  = 25, 
     DFNT_FLOAT32 = 5, 
     DFNT_FLOAT64 = 6, 
     DFNT_NINT8  = DFNT_NATIVE | DFNT_INT8, 
     DFNT_NUINT8  = DFNT_NATIVE | DFNT_UINT8, 
     DFNT_NINT16  = DFNT_NATIVE | DFNT_INT16, 
     DFNT_NUINT16 = DFNT_NATIVE | DFNT_UINT16, 
     DFNT_NINT32  = DFNT_NATIVE | DFNT_INT32, 
     DFNT_NUINT32 = DFNT_NATIVE | DFNT_UINT32, 
     DFNT_NFLOAT32 = DFNT_NATIVE | DFNT_FLOAT32, 
     DFNT_NFLOAT64 = DFNT_NATIVE | DFNT_FLOAT64 
    } 

    public enum AccessCodes 
    { 
     DFACC_READ  = 1, 
     DFACC_WRITE  = 2, 
     DFACC_CREATE = 4, 
     DFACC_ALL  = 7, 
     DFACC_RDONLY = 1, 
     DFACC_RDWR  = 3 
    } 

    #endregion 

    #region Helper Functions 

    public static double[] SDgetdimscaledouble(int dim_id, int size) 
    { 
     double d = 0; 
     IntPtr p = Marshal.AllocHGlobal(Marshal.SizeOf(d) * size); 
     SDgetdimscale(dim_id, p); 
     double[] dest = new double[size]; 
     Marshal.Copy(p, dest, 0, size); 
     Marshal.FreeHGlobal(p); 
     return dest; 
    } 

    public static void SDsetdimscaledouble(int dim_id, double[] d) 
    { 
     IntPtr p = Marshal.AllocHGlobal(Marshal.SizeOf(d[0])*d.Length); 
     Marshal.Copy(d, 0, p, d.Length); 
     int res = SDsetdimscale(dim_id, d.Length, DataTypeDefinitions.DFNT_FLOAT64, p); 
     Marshal.FreeHGlobal(p); 
    } 

    public static double SDreaddouble(int sds_id, int[] start, int[] edge) 
    { 
     double d = 0; 
     IntPtr p = Marshal.AllocHGlobal(Marshal.SizeOf(d)); 
     SDreaddata(sds_id, start, null, edge, p); 
     double[] dest = new double[1]; 
     Marshal.Copy(p, dest, 0, 1); 
     d = dest[0]; 
     Marshal.FreeHGlobal(p); 
     return d; 
    } 

    public static void SDwritedouble(int sds_id, int[] start, int[] edge, double d) 
    { 
     IntPtr p = Marshal.AllocHGlobal(Marshal.SizeOf(d)); 
     double[] a = new double[1]; 
     a[0] = d; 
     Marshal.Copy(a, 0, p, 1); 
     int res = SDwritedata(sds_id, start, null, edge, p); 
     Marshal.FreeHGlobal(p); 
    } 

    #endregion 
}

所以从这个，你可以为文件创建对象，数据集，维度，属性等。对于文件，这里有一个片段：

public class HDFFile : IDisposable 
{ 
    // snip 

    public static HDFFile New(string fullfilename) 
    { 
     HDFFile hdf = new HDFFile(fullfilename); 

     hdf._sdId = HDF4.SDstart(fullfilename, HDF4.AccessCodes.DFACC_CREATE); 

     return hdf; 
    } 

    public static HDFFile Open(string fullfilename) 
    { 
     HDFFile hdf = new HDFFile(fullfilename); 

     hdf._sdId = HDF4.SDstart(fullfilename, HDF4.AccessCodes.DFACC_RDWR); 

     if (hdf._sdId == -1) 
      throw new Exception("Could not open " + fullfilename); 

     hdf.Load(); 

     return hdf; 
    } 

    private void Load() 
    { 
     int num_ds = 0; 
     int num_global = 0; 
     HDF4.SDfileinfo(_sdId, out num_ds, out num_global); 

     for (int i = 0; i < num_ds; i++) 
     { 
      HDFDataSet hds = HDFDataSet.Load(_sdId, i); 
      if (!string.IsNullOrEmpty(hds.Name)) 
       _dataSets.Add(hds); 
     } 

     _attributes = HDFAttribute.Load(_sdId, num_global); 
    } 

    // snip 
}

来源

2010-05-14 19:30:56

1

有在现场不支持的解决方案，您发布

ftp://ftp.hdfgroup.uiuc.edu/pub/outgoing/hdf5/HDF5dotNetEnv/

来源

2009-11-30 12:22:31

+0

谢谢你的链接。不幸的是，这种解决方案仅适用于HDF5格式，但我的数据存储在HDF4中。看起来我应该使用转换器，或寻找其他解决方案.. – Gart 2009-11-30 13:35:58

0

一个更好的方法是抽象的来自HDF对象本身的元数据; HDF小组正在开发一个映射工具，用于转储有关如何从HDF文件（例如SDS，RIS，VData等）获取原始数据类型的信息，以便您可以编写自己的阅读器而无需使用HDF/Net CDF库。

http://www.hdfgroup.org/projects/h4map/