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ALGorithm
ALGorithm:FUNCtion:DEFine
Parameters
Comments
176 HP E1415 Command Reference
ALGorithm:FUNCtion:DEFine '< function_name >',< range >,< offset >,
< func_data >
defines a custom function that can be called from within a custom
algorithm. See Appendix F page 367 "Generating User Defined Functions" for full
information.
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 E1415'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 only
17µseconds. 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 a program
supplied with your HP E1415. It is provided in C-SCPI, and HP Basic forms.
See Appendix F page 367 "Generating User Defined Functions" for full
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:
O116 = squareroot( 2 * Input_val );
•
Functions must be defined before defining algorithms that reference them.
Range of
Values
valid 'C' identifier
(if not already defined in 'GLOBALS')
see comments
see comments
see comments
Default
Units
none
none
none
none
Chapter 6
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