/// <summary>
/// Read a part of the variable from file, given a certain stride
/// </summary>
/// <param name="ncVariable"></param>
/// <param name="origin"></param>
/// <param name="shape">When shape is -1, this corresponds to reading that entire dimension</param>
/// <param name="stride"></param>
/// <returns></returns>
public Array Read(NetCdfVariable ncVariable, int[] origin, int[] shape, int[] stride)
{
CreateShapeForFullRange(ncVariable, ref shape);
var count = Enumerable.Range(0, origin.Length).Select(i => (shape[i] - origin[i]) / stride[i]).ToArray();
var size = NetCdfFileHelper.GetSize(count);
var originPtr = NetCdfFileHelper.ConvertToIntPtr(origin);
var stridePtr = NetCdfFileHelper.ConvertToIntPtr(stride);
var countPtr = NetCdfFileHelper.ConvertToIntPtr(count);
var type = GetDataType(ncVariable);
switch (type)
{
case NetCdfDataType.NC_BYTE:
var byteArray = new byte[size];
CheckResult(NetCdfWrapper.nc_get_vars(id, ncVariable, originPtr, countPtr, stridePtr, byteArray));
return(NetCdfFileHelper.CreateArrayFromShape(byteArray, count));
case NetCdfDataType.NC_CHAR:
if (shape.Length != 2)
{
throw new NotSupportedException(
"NetCdf: only char arrays for independent string variables supported");
}
var charArray = new byte[size];
CheckResult(NetCdfWrapper.nc_get_vars_text(id, ncVariable, originPtr, countPtr, stridePtr, charArray));
return(NetCdfFileHelper.CreateCharArrayFromShape(charArray, count));
case NetCdfDataType.NC_INT:
var intArray = new int[size];
CheckResult(NetCdfWrapper.nc_get_vars_int(id, ncVariable, originPtr, countPtr, stridePtr, intArray));
return(NetCdfFileHelper.CreateArrayFromShape(intArray, count));
case NetCdfDataType.NC_FLOAT:
var floatArray = new float[size];
CheckResult(NetCdfWrapper.nc_get_vars_float(id, ncVariable, originPtr, countPtr, stridePtr, floatArray));
return(NetCdfFileHelper.CreateArrayFromShape(floatArray, count));
case NetCdfDataType.NC_DOUBLE:
var doubleArray = new double[size];
CheckResult(NetCdfWrapper.nc_get_vars_double(id, ncVariable, originPtr, countPtr, stridePtr, doubleArray));
return(NetCdfFileHelper.CreateArrayFromShape(doubleArray, count));
default:
throw new Exception(
String.Format("Unknown type for reading NetCDF variable from file: type {0} from file {1}",
type, path));
}
}
