set_compatible_data_type: Change the type of a data block to a binary compatible type

In rjazz: Official Client for 'Jazz'

Description

Changes the type of a data block to a binary compatible type without changing its contents. This is only valid between integer types (integer, sorted and categorical) and real types (double and time). This can also be used to change within raw types.

Usage

set_compatible_data_type(source, block_key, type, host = .host.)

Arguments

source	The Jazz source. Jazz persistence is organized in sources. All sources except 'sys' and 'www' are user defined. Sources are 15 char long alphanumeric or underscore.
block_key	The key identifying the block. Keys are 15 alphanumeric or underscore characters. They can be user defined or created by new_key(). Also, meshes use block keys internally.
type	The new type of the block. Must be binary compatible with the exiting type. BLOCKTYPE_C_INTEGER to BLOCKTYPE_C_FACTOR or BLOCKTYPE_C_GRADE and BLOCKTYPE_C_REAL to BLOCKTYPE_C_TIMESEC.
host	(Optional) the name of the jazz server host (including the port). Usually set just once via set_jazz_host().

Value

TRUE or raises an error on failure.

Examples

## Not run: 
create_source('demo_types')

# Write a text file as a block.
txt <- c('Hi all,', '', 'This is a file.', '', 'bye,', 'me')
str <- paste(txt, collapse = '\n')
cat(str)

put_raw_block('demo_types', 'blk_1', str)

# The block is raw (not interpreted as data by the server) and can be converted to any raw type.
set_compatible_data_type('demo_types', 'blk_1', type_const[['BLOCKTYPE_RAW_MIME_TXT']])

# curl 127.0.0.1:8888//demo_types.blk_1 (or open in a in a browser)

get_block_attributes('demo_types', 'blk_1')

# The attribute flags is writable by the user.
put_block_flags('demo_types', 'blk_1', 123000444)

get_block_attributes('demo_types', 'blk_1')

# Unlike the previous block, this block is a data block.
put_R_block('demo_types', 'blk_2', 3:6)

# This trivial block can also be created by the server as..
create_block_seq('demo_types', 'blk_2', 3L, 6)

get_block_attributes('demo_types', 'blk_2')

# The block is interpreted as data by the server, it is an integer and can be converted to
any integer type.
set_compatible_data_type('demo_types', 'blk_2', type_const[['BLOCKTYPE_C_R_GRADE']])

get_block_attributes('demo_types', 'blk_2')

# This returns all the rows in a single string
get_block_as_string('demo_types', 'blk_2', '

# With some help of R functions, the result of get_block_as_string() can be made integer again.
any(3:6 != as.integer(strsplit(get_block_as_string('demo_types', 'blk_2', '

rs <- c('1', '2.7', '3.14')

# Creating strings into numeric data. (The parse(.., collapse = '\n') is automatic.)
put_strings_as_block('demo_types', 'blk_3', rs, type_const[['BLOCKTYPE_C_R_REAL']])

get_block_attributes('demo_types', 'blk_3')

any(as.numeric(rs) != get_R_block('demo_types', 'blk_3'))

delete_source('demo_types')

## End(Not run)

rjazz documentation built on May 2, 2019, 2:45 p.m.