Conversion Functions

Conversion functions allow you to construct new fields and convert the storage type of existing files. For example, you can form new strings by joining strings together or by taking strings apart. To join two strings, use the operator ><. For example, if the field Site has the value "BRAMLEY", then "xx" >< Site returns "xxBRAMLEY". The result of >< is always a string, even if the arguments are not strings. Thus, if field V1 is 3 and field V2 is 5, then V1 >< V2 returns "35" (a string, not a number).

Conversion functions (and any other functions that require a specific type of input, such as a date or time value) depend on the current formats specified in the Stream Options dialog box. For example, if you want to convert a string field with values Jan 2003, Feb 2003, and so on, select the matching date format MON YYYY as the default date format for the stream.

Table 1. CLEM conversion functions
Function	Result	Description
`ITEM1` >< `ITEM2`	String	Concatenates values for two fields and returns the resulting string as ITEM1ITEM2.
`to_integer(ITEM)`	Integer	Converts the storage of the specified field to an integer.
`to_real(ITEM)`	Real	Converts the storage of the specified field to a real.
`to_number(ITEM)`	Number	Converts the storage of the specified field to a number.
`to_string(ITEM)`	String	Converts the storage of the specified field to a string. When a real is converted to string using this function, it returns a value with 6 digits after the radix point.
`to_time(ITEM)`	Time	Converts the storage of the specified field to a time.
`to_date(ITEM)`	Date	Converts the storage of the specified field to a date.
`to_timestamp(ITEM)`	Timestamp	Converts the storage of the specified field to a timestamp.
`to_datetime(ITEM)`	Datetime	Converts the storage of the specified field to a date, time, or timestamp value.
`datetime_date(ITEM)`	Date	Returns the date value for a number, string, or timestamp. Note this is the only function that allows you to convert a number (in seconds) back to a date. If `ITEM` is a string, creates a date by parsing a string in the current date format. The date format specified in the stream properties dialog box must be correct for this function to be successful. If `ITEM` is a number, it is interpreted as a number of seconds since the base date (or epoch). Fractions of a day are truncated. If `ITEM` is a timestamp, the date part of the timestamp is returned. If `ITEM` is a date, it is returned unchanged.
`stb_centroid_latitude(ITEM)`	Integer	Returns an integer value for latitude corresponding to centroid of the geohash argument.
`stb_centroid_longitude(ITEM)`	Integer	Returns an integer value for longitude corresponding to centroid of the geohash argument.
`to_geohash(ITEM)`	String	Returns the geohashed string corresponding to the latitude and longitude using the specified number of bits for the density. A geohash is a code used to identify a set of geographic coordinates based on the latitude and longitude details. The three parameters for `to_geohash` are: latitude: Range (-180, 180), and units are degrees in the WGS84 coordinate system longitude: Range (-90, 90), and units are degrees in the WGS84 coordinate system bits: The number of bits to use to store the hash. Range [1,75]. This affects both the length of the returned string (1 character is used for every 5 bits), and the accuracy of the hash. For example, 5 bits (1 character) represents approximately 2500 kilometers, or 45 bits (9 characters), represents approximately 2.3 meters.