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Reads a binary data file and returns the values as a series.
FREADB("filename", filetype, length, byteswap)
|
"filename" |
- |
A string, the name of the source file. |
|
filetype |
- |
An integer, the binary format type of the data file described by either its name or integer code. Valid arguments are: |
|
Name |
Code |
Data Type |
Range |
|
INT8 SBYTE |
1 |
8-bit Signed Byte |
-128 to +127 |
|
UINT8 UBYTE BYTE |
2 |
8-bit Unsigned Byte |
0 to 255 |
|
INT16 SINT |
3 |
16-bit (2-byte) Signed Integer |
-32768 to +32767 |
|
UINT16 UINT |
4 |
16-bit (2-byte) Unsigned Integer |
0 to 65535 |
|
INT32 LONG |
5 |
32-bit (4-byte) Signed Integer |
-2,147,483,648 to +2,147,483,647 |
|
FLOAT |
6 |
32-bit (4-byte) Floating Point |
-1037 to +1038 |
|
DOUBLE |
7 |
64-bit (8-byte) Floating Point |
-10-307 to +10308 |
|
UINT32 ULONG |
8 |
32-bit (4-byte) Unsigned Integer |
0 to 4,294,967,295 |
|
INT64 |
9 |
64-bit (8-byte) Signed Integer |
-9,223,372,036,854,775,808 to +9,223,372,036,854,775,807 |
|
UINT64 |
10 |
64-bit (8-byte) Unsigned Integer |
0 to 18,446,744,073,709,551,615 |
|
|
1000 + N |
N-byte Signed Integer |
-28N-1 to 28N-1-1 |
|
|
2000 + N |
N-byte Unsigned Integer |
0 to 28N-1 |
|
length |
- |
Optional. An integer. The number of data points to read. If length is set to -1, the entire file is read. Defaults to -1. |
||||
|
byteswap |
- |
Optional. An integer. Swap the order of the bytes read.
|
A series.
writeb("mix.dat", float, 1, {1.5, 2.5, 3.5})
writeb("mix.dat", sint, 2, {10, -20})
fopen("mix.bin", "rb")
a = freadb("mix.bin", float, 3);
b = freadb("mix.bin", sint, 2)
fclose("mix.bin")
a == {1.5, 2.5, 3.5}
b == {10, -20}
The WRITEB function creates a file that contains 3 float values and then appends 2 signed integer values. FREADB reads the values into the series variables.
fopen("mix.bin", "rb")
fseek("mix.bin", 8, 0)
c = castreal(freadb("mix.bin", float, 1));
fclose("mix.bin")
c == 3.5
The FSEEK positions the file at the third float value by skipping the first 8 bytes. FREADB reads the float value as a one point series. The CASTREAL function converts the series into a real scalar.
fopen("speech.dat", "rb")
dbser = freadb("speech.dat", DOUBLE, -1)
fcloseall
returns a series that contains all the data in speech.dat read as doubles.
File must be opened with FOPEN before using FREADB. Use the "rb" mode to open a binary file in read mode.
FREADB is like READB once FOPEN is used to open the file.
FREADB always returns a series. To return a scalar, use GETPT or the CAST functions. For example, to read a single integer from a file:
fopen("test.dat", "rb")
iser = freadb("test.dat", SINT, 1)
ival = castint(iser)