HP E1419A User Manual page 203

ALGorithm
Parameters
Comments
Usage
202 HP E1419 Command Reference
Parameter Parameter
Name Type
function_name string
range numeric (float32)
offset numeric (float32)
func_data 512 element array
of uint16
•
By providing this custom function capability, the HP E1419's algorithm language
can be kept simple in terms of mathematical capability. This increases speed.
Rather than having to calculate high-order polynomial approximations of
non-linear functions, this custom function scheme loads a pre-computed look-up
table of values into memory. This method allows computing virtually any
transcendental or non-linear function in about 18µseconds. Resolution is 16 bits.
•
<function_name> is a global identifier and cannot be the same as a previously
define global variable. A user function is globally available to all defined
algorithms.
•
You generate values for <range>, <offset>, and <func_data> with the HP VEE
program "fn_1419.vee" supplied with your HP E1419. See Appendix E
"Generating User Defined Functions" for background information.
•
<range>, and <offset> define the allowable input values to the function (domain).
If values input to the function are equal to or outside of (±<range>+<offset>), the
function may return ±INF in IEEE-754 format. For example; <range> = 8 (-8 to
8), <offset> = 12. The allowable input values must be greater than 4 and less than
20.
•
<func_data> is a 512 element array of type uint16.
•
The algorithm syntax for calling is: <function_name> ( <expression> ). for
example:
O136 = squareroot( 2 * Input_val );
•
Functions must be defined before defining algorithms that reference them.
•
When Accepted: Before INIT only.
ALG:FUNC:DEF 'F1',8,12,< block_data >
Range of
Values
valid 'C' identifier
(if not already defined in 'GLOBALS')
see comments
see comments
see comments
send range, offset and table values for
function F1
Default
Units
none
none
none
none
Chapter 6