I am trying to read a binary file and parse the bytes I have the white paper spec on Shapefiles to know how to parse the file, however I cannot seem to find the correct functions in ColdFusion to handle reading bytes and deciding what to do with them.
<cffile action="READBINARY"
file="mypath/www/_Dev/tl_2009_25_place.shp"
variable="infile" >
PDF file with spec:http://www.esri.com/library/whitepapers/pdfs/shapefile.pdf
For example I have the spec:
Position Field Value Type Order
Byte 0 File Code 9994 Integer Big
Byte 4 Unused 0 Integer Big
Byte 8 Unused 0 Integer Big
Byte 12 Unused 0 Integer Big
Byte 16 Unused 0 Integer Big
Byte 20 Unused 0 Integer Big
Byte 24 File Length File Length Integer Big
Byte 28 Version 1000 Integer Little
Byte 32 Shape Type Shape Type Integer Little
Byte 36 Bounding Box Xmin Double Little
Byte 44 Bounding Box Ymin Double Little
Byte 52 Bounding Box Xmax Double Little
Byte 60 Bounding Box Ymax Double Little
Byte 68* Bounding Box Zmin Double Little
Byte 76* Bounding Box Zmax Double Little
Byte 84* Bounding Box Mmin Double Little
Byte 92* Bounding Box Mmax Double Little
If this was just a flat text file i would use mid function to read my positions.
Can this be done in ColdFusion and Which functions can achieve my goal?
I found this function inside of FarStream.as found at http://code.google.com/p/vanrijkom-flashlibs/wiki/SHP which is an Actionscript3 file, but it represents the kind of task i need to do.
private function readHeader(e: ProgressEvent): void {
// check header:
if (! ( readByte()==0x46
&& readByte()==0x41
&& readByte()==0x52
))
{
dispatchEvent(new IOErrorEvent
( IOErrorEvent.IO_ERROR
, false,false
, "File is not FAR formatted")
);
close();
return;
}
// version:
vMajor = readByte();
vMinor = readByte();
if (vMajor>VMAJOR) {
dispatchEvent(new IOErrorEvent
( IOErrorEvent.IO_ERROR
, false,false
, "Unsupported archive version (v."+vMajor+"."+vMinor+")")
);
close();
return;
}
// table size:
tableSize = readUnsignedInt();
// done processing header:
gotHeader= true;
}
And here is the final solution
<cfset shapeFile = createObject("java","com.bbn.openmap.layer.shape.ShapeFile").init('/www/_Dev/tl_2009_25_place.shp')>
<cfdump var="#shapeFile.getFileLength()#">
<cffile action="READBINARY" file="mypath/www/_Dev/tl_2009_25_place.shp" variable="infile" >
<cfset shapeFile = createObject("java","com.bbn.openmap.layer.shape.ShapeFile").init(infile)>
<cfdump var="#shapeFile#">
Maybe something like this?
Related
I'm looking for how to turn bytes into a signed int using lua 5.1.5, so far I've only been able to find solutions for lua 5.2 onward, and they are not backward compatible.
I have solutions for how to turn bytes into unsigned integers, like so:
payload_t.temperature=tonumber(utility.hex2str(string.sub(payload,32,33)),16)
First of all I'll assume that you actually have a byte string rather than a hex string given; if your string is a hex string, you can trivially convert it to a byte string using gsub:
function hex2bytes(str)
-- assert that it is indeed a string of hex digit pairs
assert(#str % 2 == 0 and not str:match"[^%x]")
return str:gsub("%x%x", function(hex) return tonumber(hex, 16) end)
end
Now, let's convert this byte string to an integer. I'll assume little endian (least significant byte first); should your string be big endian (most significant byte first) you'll have to reverse it using str:reverse() before you read it.
Reading an unsigned integer is pretty straightforward:
function bytes2uint(str)
local uint = 0
for i = 1, #str do
uint = uint + str:byte(i) * 0x100^(i-1)
end
return uint
end
I'll assume your integers are stored using Two's complement. In this case the higher 2^n values (equivalent to the first bit being set or the value being >= 2^(n-1)) the uint can take represent negative numbers, with the smallest value (2^(n-1)) representing the largest negative value (-2^(n-1)). Thus you can simply subtract the unsigned value from 2^n, the (exclusive) max value for the uint:
function bytes2int(str)
local uint = bytes2uint(str)
local max = 0x100 ^ #str
if uint >= max / 2 then
return uint - max
end
return uint
end
byte 0: min_value (0-3 bit)
max_value (4-7 bit)
The byte0 should be the min and max values combined.
min and max values are both integers (in 0-15 range).
I should convert them into 4-bit binary, and combine them somehow? (how?)
E.g.
min_value=2 // 0010
max_value=3 // 0011
The result should be an Uint8, and the value: 00100011
You can use the shift left operator << to get the result you want:
result = ((min_value << 4) + max_value).toRadixString(2).padLeft(8, '0');
I have a coremlmodel taking an input of shape MultiArray (Float32 67 x 256 x 320)
I am having a hard time to shape the input to this model.
Currently, I am trying to achieve it like so,
var m = try! MLMultiArray(shape: [67,256,320], dataType: .double)
for i in 0...66{
var cost = rand((256,320)) // this is coming from swix [SWIX]
memcpy(m.dataPointer+i*256*320, &cur_cost.flat.grid , 256*320)
}
I will have to replace the rand with matrices of that size later. I am using this for testing purposes first.
Any pointers on how to mould input to fit the volume would be greatly appreciated..
[SWIX]
What seems to be wrong in your code is that you're copying bytes instead of doubles. A double is 8 bytes, so your offset should be i*256*320*MemoryLayout<Double>.stride and the amount you're copying should be 256*320*MemoryLayout<Double>.stride.
Note that you can also use the MLMultiArray's strides property to compute the offset for a given data element in the array:
let offset = i0 * strides[0].intValue + i1 * strides[1].intValue + i2 * strides[2].intValue
I wrote a code that can get line projection (intensity profile) of an image, and I would like to convert/export this line projection (intensity profile) to excel table, and then order all the Y coordinate. For example, except the maximum and minimum values of all the Y coordinate, I would like to know largest 5 coordinate value and smallest coordinate value.
Is there any code can reach this function? Thanks,
image line_projection
Realimage imgexmp
imgexmp := GetFrontImage()
number samples = 256, xscale, yscale, xsize, ysize
GetSize( imgexmp, xsize, ysize )
line_projection := CreateFloatImage( "line projection", Xsize, 1 )
line_projection = 0
line_projection[icol,0] += imgexmp
line_projection /= samples
ShowImage( line_projection )
Finding a 'sorted' list of values
If you need to sort though large lists of values (i.e. large images) the following might not be very sufficient. However, if your aim is to get the "x highest" values with a relatively small number of X, then the following code is just fine:
number nFind = 10
image test := GetFrontImage().ImageClone()
Result( "\n\n" + nFind + " highest values:\n" )
number x,y,v
For( number i=0; i<nFind; i++ )
{
v = max(test,x,y)
Result( "\t" + v + " at " + x + "\n" )
test[x,y] = - Infinity()
}
Working with a copy and subsequently "removing" the maximum value by changing that pixel value. The max command is fast - even for large images -, but the for-loop iteration and setting of individual pixels is slow. Hence this script is too slow for a complete 'sorting' of the data if it is big, but it can quickly get you the n 'highest' values.
This is a non-coding answer:
If you havea LinePlot display in DigitalMicrograph, you can simply copy-paste that into Excel to get the numbers.
i.e. with the LinePlot image front most, preses CTRL + C to copy
(make sure there are no ROIs on it).
Switch to Excel and press CTRL + V. Done.
==>
I'm trying the second day to send a midi signal. I'm using following code:
int pitchValue = 8191 //or -8192;
int msb = ?;
int lsb = ?;
UInt8 midiData[] = { 0xe0, msb, lsb};
[midi sendBytes:midiData size:sizeof(midiData)];
I don't understand how to calculate msb and lsb. I tried pitchValue << 8. But it's working incorrect, When I'm looking to events using midi tool I see min -8192 and +8064 max. I want to get -8192 and +8191.
Sorry if question is simple.
Pitch bend data is offset to avoid any sign bit concerns. The maximum negative deviation is sent as a value of zero, not -8192, so you have to compensate for that, something like this Python code:
def EncodePitchBend(value):
''' return a 2-tuple containing (msb, lsb) '''
if (value < -8192) or (value > 8191):
raise ValueError
value += 8192
return (((value >> 7) & 0x7F), (value & 0x7f))
Since MIDI data bytes are limited to 7 bits, you need to split pitchValue into two 7-bit values:
int msb = (pitchValue + 8192) >> 7 & 0x7F;
int lsb = (pitchValue + 8192) & 0x7F;
Edit: as #bgporter pointed out, pitch wheel values are offset by 8192 so that "zero" (i.e. the center position) is at 8192 (0x2000) so I edited my answer to offset pitchValue by 8192.