zeBIO

Use .new("bio") to create the object for general binrary intput/output of data. A special functions is included to read the world coastline data (GHSSG); and another to read regular grid GRIB data.

:open(file)

Opens the file for reading.

:open(file, "w")

Opens the file for witing.

:read(bytes)

Reads the specified number of bytes from the file.

:write(ptr, bytes)

Writes the specified number of bytes pointed to by ptr to the file.

:byte(index)

Returns the byte at the index.

:byteswitch(bytes)

Switches byte for every number of specified bytes in the byte-array.

:seek(offset)

Moves the file pointer by the offset from the current position.

:rewind()

Moves the file pointer to the beginning.

:gotoend()

Moves the file pointer to the end.

:tell()

Returns the current position of the file pointer.

:size()

Returns the file size in byte.

:getptr()

Returns the pointer to the byte array, the array size, and the number of bytes read from the file.

:transfer(ptr, nb)

Transfer nb bytes from the object to the lightuserdata ptr. The parameter nb must be less than or equal to the number of bytes already read.

:gshhs(flag, west, east, south, north, arr)

Reads coastline data from a GSHHS files to the array arr. The flag parameter ("land", "lake", "island", or "pond") specifies which dataset to read; the west and east parameters specify the longitude range (0 to 360 degree); and the south and north parameters specify the latitude range (-90 to 90 degree).

:grib()

Displays parameter id, pressure layer, date, and region code in the opened GRIB file.

:grib(id, pressure, year, month, day, hour, arr)

Reads the dataset with the id on the pressure layer at that time. The data will be saved in the array arr.