private GRIB_Point[] SimpleUnpacking(FileStream fs, IGRIB2GridDefinitionSection gds, IGRIB2DataRepresentationSection drs, IGribBitMapSection bms)
{
// dataPoints are number of points encoded, it could be less than the
// numberPoints in the grid record if bitMap is used, otherwise equal
_bitPos = 0;
_bitBuf = 0;
int dataPoints = drs.DataPoints;
float pmv = drs.PrimaryMissingValue;
int nb = drs.NumberOfBits;
int D = drs.DecimalScaleFactor;
float DD = (float)System.Math.Pow((double)10, (double)D);
float R = drs.ReferenceValue;
int E = drs.BinaryScaleFactor;
float EE = (float)System.Math.Pow((double)2.0, (double)E);
int numberPoints = gds.PointsNumber;
GRIB_Point[] data = new GRIB_Point[numberPoints];
bool[] bitmap = bms.Bitmap;
// Y * 10**D = R + (X1 + X2) * 2**E
// E = binary scale factor
// D = decimal scale factor
// R = reference value
// X1 = 0
// X2 = scaled encoded value
// data[ i ] = (R + ( X1 + X2) * EE)/DD ;
if (bitmap == null)
{
for (int i = 0; i < numberPoints; i++)
{
data[i].Index = i;
data[i].Value = (R + Bits2UInt(nb, fs) * EE) / DD;
}
}
else
{
for (int i = 0; i < bitmap.Length; i++)
{
data[i].Index = i;
if (bitmap[i])
{
//data[ i ] = (R + ( X1 + X2) * EE)/DD ;
data[i].Value = (R + Bits2UInt(nb, fs) * EE) / DD;
}
else
{
data[i].Value = pmv;
}
}
}
return(data);
}
public void StatMinMax(GRIB_Point[] pts, out GRIB_Point minPoint, out GRIB_Point maxPoint)
{
throw new NotImplementedException();
}
private GRIB_Point[] ComplexUnpackingWithSpatial(FileStream fs, IGRIB2GridDefinitionSection gds, IGRIB2DataRepresentationSection drs)
{
int mvm = drs.MissingValueManagement;
float pmv = drs.PrimaryMissingValue;
int NG = drs.NumberOfGroups;
int g1 = 0, gMin = 0, h1 = 0, h2 = 0, hMin = 0;
// [6-ww] 1st values of undifferenced scaled values and minimums
int os = drs.OrderSpatial;
int ds = drs.DescriptorSpatial;
_bitPos = 0; _bitBuf = 0;
int sign;
// ds is number of bytes, convert to bits -1 for sign bit
ds = ds * 8 - 1;
if (os == 1)
{
// first order spatial differencing g1 and gMin
sign = Bits2UInt(1, fs);
g1 = Bits2UInt(ds, fs);
if (sign == 1)
{
g1 *= (-1);
}
sign = Bits2UInt(1, fs);
gMin = Bits2UInt(ds, fs);
if (sign == 1)
{
gMin *= (-1);
}
}
else if (os == 2)
{
//second order spatial differencing h1, h2, hMin
sign = Bits2UInt(1, fs);
h1 = Bits2UInt(ds, fs);
if (sign == 1)
{
h1 *= (-1);
}
sign = Bits2UInt(1, fs);
h2 = Bits2UInt(ds, fs);
if (sign == 1)
{
h2 *= (-1);
}
sign = Bits2UInt(1, fs);
hMin = Bits2UInt(ds, fs);
if (sign == 1)
{
hMin *= (-1);
}
}
else
{
return(null);
}
// [ww +1]-xx Get reference values for groups (X1's)
int[] X1 = new int[NG];
int nb = drs.NumberOfBits;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
X1[i] = Bits2UInt(nb, fs);
}
// [xx +1 ]-yy Get number of bits used to encode each group
int[] NB = new int[NG];
nb = drs.BitsGroupWidths;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
NB[i] = Bits2UInt(nb, fs);
}
// [yy +1 ]-zz Get the scaled group lengths using formula
// Ln = ref + Kn * len_inc, where n = 1-NG,
// ref = referenceGroupLength, and len_inc = lengthIncrement
int[] L = new int[NG];
int countL = 0;
int ref_Renamed = drs.ReferenceGroupLength;
int len_inc = drs.LengthIncrement;
nb = drs.BitsScaledGroupLength;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
// NG
L[i] = ref_Renamed + (Bits2UInt(nb, fs) * len_inc);
countL += L[i];
}
// [zz +1 ]-nn get X2 values and add X1[ i ] + X2
GRIB_Point[] data = new GRIB_Point[countL];
// used to check missing values when X2 is packed with all 1's
int[] bitsmv1 = new int[31];
for (int i = 0; i < 31; i++)
{
bitsmv1[i] = (int)System.Math.Pow((double)2, (double)i) - 1;
}
int count = 0;
int X2;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG - 1; i++)
{
for (int j = 0; j < L[i]; j++)
{
data[count].Index = count;
if (NB[i] == 0)
{
if (mvm == 0)
{
// X2 = 0
data[count++].Value = X1[i];
}
else if (mvm == 1)
{
data[count++].Value = pmv;
}
}
else
{
X2 = Bits2UInt(NB[i], fs);
if (mvm == 0)
{
data[count++].Value = X1[i] + X2;
}
else if (mvm == 1)
{
// X2 is also set to missing value is all bits set to 1's
if (X2 == bitsmv1[NB[i]])
{
data[count++].Value = pmv;
}
else
{
data[count++].Value = X1[i] + X2;
}
}
}
}
}
// process last group
int last = drs.LengthLastGroup;
for (int j = 0; j < last; j++)
{
data[count].Index = count;
// last group
if (NB[NG - 1] == 0)
{
if (mvm == 0)
{
// X2 = 0
data[count++].Value = X1[NG - 1];
}
else if (mvm == 1)
{
data[count++].Value = pmv;
}
}
else
{
X2 = Bits2UInt(NB[NG - 1], fs);
if (mvm == 0)
{
data[count++].Value = X1[NG - 1] + X2;
}
else if (mvm == 1)
{
// X2 is also set to missing value is all bits set to 1's
if (X2 == bitsmv1[NB[NG - 1]])
{
data[count++].Value = pmv;
}
else
{
data[count++].Value = X1[NG - 1] + X2;
}
}
}
}
if (os == 1)
{
// g1 and gMin this coding is a sort of guess, no doc
float sum = 0;
if (mvm == 0)
{
// no missing values
for (int i = 1; i < data.Length; i++)
{
data[i].Value += gMin; // add minimum back
}
data[0].Value = g1;
for (int i = 1; i < data.Length; i++)
{
sum += data[i].Value;
data[i].Value = data[i - 1].Value + sum;
}
}
else
{
// contains missing values
float lastOne = pmv;
// add the minimum back and set g1
int idx = 0;
for (int i = 0; i < data.Length; i++)
{
if (data[i].Value != pmv)
{
if (idx == 0)
{
// set g1
data[i].Value = g1;
lastOne = data[i].Value;
idx = i + 1;
}
else
{
data[i].Value += gMin;
}
}
}
if (lastOne == pmv)
{
return(data);
}
for (int i = idx; i < data.Length; i++)
{
if (data[i].Value != pmv)
{
sum += data[i].Value;
data[i].Value = lastOne + sum;
lastOne = data[i].Value;
}
}
}
}
else if (os == 2)
{
//h1, h2, hMin
float hDiff = h2 - h1;
float sum = 0;
if (mvm == 0)
{
// no missing values
for (int i = 2; i < data.Length; i++)
{
data[i].Value += hMin; // add minimum back
}
data[0].Value = h1;
data[1].Value = h2;
sum = hDiff;
for (int i = 2; i < data.Length; i++)
{
sum += data[i].Value;
data[i].Value = data[i - 1].Value + sum;
}
}
else
{
// contains missing values
int idx = 0;
float lastOne = pmv;
// add the minimum back and set h1 and h2
for (int i = 0; i < data.Length; i++)
{
if (data[i].Value != pmv)
{
if (idx == 0)
{
// set h1
data[i].Value = h1;
sum = 0;
lastOne = data[i].Value;
idx++;
}
else if (idx == 1)
{
// set h2
data[i].Value = h1 + hDiff;
sum = hDiff;
lastOne = data[i].Value;
idx = i + 1;
}
else
{
data[i].Value += hMin;
}
}
}
if (lastOne == pmv)
{
return(data);
}
for (int i = idx; i < data.Length; i++)
{
if (data[i].Value != pmv)
{
sum += data[i].Value;
data[i].Value = lastOne + sum;
lastOne = data[i].Value;
}
}
}
} // end h1, h2, hMin
// formula used to create values, Y * 10**D = R + (X1 + X2) * 2**E
int D = drs.DecimalScaleFactor;
float DD = (float)System.Math.Pow((double)10, (double)D);
float R = drs.ReferenceValue;
int E = drs.BinaryScaleFactor;
float EE = (float)System.Math.Pow((double)2.0, (double)E);
if (mvm == 0)
{
// no missing values
for (int i = 0; i < data.Length; i++)
{
data[i].Value = (R + data[i].Value * EE) / DD;
}
}
else
{
// missing value == 1
for (int i = 0; i < data.Length; i++)
{
if (data[i].Value != pmv)
{
data[i].Value = (R + data[i].Value * EE) / DD;
}
}
}
ScanningModeCheck(data, gds.ScanMode, gds.Nx);
return(data);
}
private GRIB_Point[] ComplexUnpacking(FileStream fs, IGRIB2GridDefinitionSection gds, IGRIB2DataRepresentationSection drs)
{
int mvm = drs.MissingValueManagement;
float pmv = drs.PrimaryMissingValue;
int NG = drs.NumberOfGroups;
// 6-xx Get reference values for groups (X1's)
int[] X1 = new int[NG];
int nb = drs.NumberOfBits;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
X1[i] = Bits2UInt(nb, fs);
}
// [xx +1 ]-yy Get number of bits used to encode each group
int[] NB = new int[NG];
nb = drs.BitsGroupWidths;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
NB[i] = Bits2UInt(nb, fs);
}
// [yy +1 ]-zz Get the scaled group lengths using formula
// Ln = ref + Kn * len_inc, where n = 1-NG,
// ref = referenceGroupLength, and len_inc = lengthIncrement
int[] L = new int[NG];
int countL = 0;
int ref_Renamed = drs.ReferenceGroupLength;
int len_inc = drs.LengthIncrement;
nb = drs.BitsScaledGroupLength;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG; i++)
{
// NG
L[i] = ref_Renamed + (Bits2UInt(nb, fs) * len_inc);
countL += L[i];
}
// [zz +1 ]-nn get X2 values and calculate the results Y using formula
// Y * 10**D = R + (X1 + X2) * 2**E
int D = drs.DecimalScaleFactor;
float DD = (float)System.Math.Pow((double)10, (double)D);
float R = drs.ReferenceValue;
int E = drs.BinaryScaleFactor;
float EE = (float)System.Math.Pow((double)2.0, (double)E);
GRIB_Point[] data = new GRIB_Point[countL];
int count = 0;
int[] bitsmv1 = new int[31];
for (int i = 0; i < 31; i++)
{
bitsmv1[i] = (int)System.Math.Pow((double)2, (double)i) - 1;
}
int X2;
_bitPos = 0;
_bitBuf = 0;
for (int i = 0; i < NG - 1; i++)
{
for (int j = 0; j < L[i]; j++)
{
data[count].Index = count;
if (NB[i] == 0)
{
if (mvm == 0)
{
// X2 = 0
data[count++].Value = (R + X1[i] * EE) / DD;
}
else if (mvm == 1)
{
data[count++].Value = pmv;
}
}
else
{
X2 = Bits2UInt(NB[i], fs);
if (mvm == 0)
{
data[count++].Value = (R + (X1[i] + X2) * EE) / DD;
}
else if (mvm == 1)
{
// X2 is also set to missing value is all bits set to 1's
if (X2 == bitsmv1[NB[i]])
{
data[count++].Value = pmv;
}
else
{
data[count++].Value = (R + (X1[i] + X2) * EE) / DD;
}
}
}
}
}
// process last group
int last = drs.LengthLastGroup;
for (int j = 0; j < last; j++)
{
data[count].Index = count;
// last group
if (NB[NG - 1] == 0)
{
if (mvm == 0)
{
// X2 = 0
data[count++].Value = (R + X1[NG - 1] * EE) / DD;
}
else if (mvm == 1)
{
data[count++].Value = pmv;
}
}
else
{
X2 = Bits2UInt(NB[NG - 1], fs);
if (mvm == 0)
{
data[count++].Value = (R + (X1[NG - 1] + X2) * EE) / DD;
}
else if (mvm == 1)
{
// X2 is also set to missing value is all bits set to 1's
if (X2 == bitsmv1[NB[NG - 1]])
{
data[count++].Value = pmv;
}
else
{
data[count++].Value = (R + (X1[NG - 1] + X2) * EE) / DD;
}
}
}
} // end for j
ScanningModeCheck(data, gds.ScanMode, gds.Nx);
return(data);
}
public GRIB_Point[] Read()
{
try
{
if (_fs != null)
{
IGribBitMapSection bms = null;
GRIB_Point[] points = null;
bool isConstant = false;
_fs.Seek(_dataOffset, SeekOrigin.Begin);
if (_isBmsExist)
{
bms = new Grib1BitMapSection(_fs);
}
// octets 1-3 (section _length)
int dataLength = GribNumberHelper.Uint3(_fs);
// octet 4, 1st half (packing flag)
int unusedbits = _fs.ReadByte();
if ((unusedbits & 192) != 0)
{
throw new NotSupportedException("BDS: (octet 4, 1st half) not grid point data and simple packing ");
}
// octet 4, 2nd half (number of unused bits at end of this section)
unusedbits = unusedbits & 15;
// octets 5-6 (binary scale factor)
int binscale = GribNumberHelper.Int2(_fs);
// octets 7-10 (reference point = minimum value)
float refvalue = GribNumberHelper.Float4(_fs);
// octet 11 (number of bits per value)
int numbits = _fs.ReadByte();
if (numbits == 0)
{
isConstant = true;
}
float refRenamed = (float)(Math.Pow(10.0, -_decscale) * refvalue);
float scale = (float)(System.Math.Pow(10.0, -_decscale) * System.Math.Pow(2.0, binscale));
if (_firstlat == 0 & _lastlat == 90)
{
if (bms != null)
{
bool[] bitmap = bms.Bitmap;
points = new GRIB_Point[bitmap.Length];
for (int i = 0; i < bitmap.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
if (bitmap[i])
{
if (!isConstant)
{
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
else
{
// rdg - added this to handle a constant valued parameter
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed;
}
}
else
{
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = -9999f;
}
}
}
else
{
if (!isConstant)
{
points = new GRIB_Point[((dataLength - 11) * 8 - unusedbits) / numbits];
for (int i = 0; i < points.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
}
else
{
// constant valued - same min and max
int x = 0, y = 0;
_fs.Seek(_fs.Position - 53, SeekOrigin.Begin); // return to start of GDS
dataLength = (int)GribNumberHelper.Uint3(_fs);
if (dataLength == 42)
{
// Lambert/Mercator offset
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
_fs.Seek(7, SeekOrigin.Current);
dataLength = GribNumberHelper.Uint3(_fs);
if (dataLength == 32)
{
// Polar sterographic
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
x = y = 1;
}
}
points = new GRIB_Point[x * y];
for (int i = 0; i < points.Length; i++)
{
int m = (_height - (int)(i / _width) - 1) * _width + (i % _width);
points[m] = new GRIB_Point();
points[m].Index = i;
points[m].Value = refRenamed;
}
}
}
}
else
{
if (bms != null)
{
bool[] bitmap = bms.Bitmap;
points = new GRIB_Point[bitmap.Length];
for (int i = 0; i < bitmap.Length; i++)
{
if (bitmap[i])
{
if (!isConstant)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
else
{
// rdg - added this to handle a constant valued parameter
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed;
}
}
else
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = -9999f;
}
}
}
else
{
if (!isConstant)
{
points = new GRIB_Point[((dataLength - 11) * 8 - unusedbits) / numbits];
for (int i = 0; i < points.Length; i++)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed + scale * Bits2UInt(numbits, _fs);
}
}
else
{
// constant valued - same min and max
int x = 0, y = 0;
_fs.Seek(_fs.Position - 53, SeekOrigin.Begin); // return to start of GDS
dataLength = (int)GribNumberHelper.Uint3(_fs);
if (dataLength == 42)
{
// Lambert/Mercator offset
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
_fs.Seek(7, SeekOrigin.Current);
dataLength = GribNumberHelper.Uint3(_fs);
if (dataLength == 32)
{
// Polar sterographic
_fs.Seek(3, SeekOrigin.Current);
x = GribNumberHelper.Int2(_fs);
y = GribNumberHelper.Int2(_fs);
}
else
{
x = y = 1;
}
}
points = new GRIB_Point[x * y];
for (int i = 0; i < points.Length; i++)
{
points[i] = new GRIB_Point();
points[i].Index = i;
points[i].Value = refRenamed;
}
}
}
}
return(points);
}
return(null);
}
finally
{
_fs.Seek(0, SeekOrigin.Begin);
}
}
