Reference Guide

3-182 Full Command and Function Reference
PTAYL
Type: Function
Description: Returns the Taylor polynomial at x = a for a specified polynomial.
Access: Arithmetic, !Þ POLYNOMIAL LL
Input: Level 2/Argument 1: A polynomial, P.
Level 1/Argument 2: A number, a.
Output: A polynomial, Q such that Q(x – a)=P(x).
Flags: Exact mode must be set (flag –105 clear).
Numeric mode must not be set (flag –3 clear).
Radians mode must be set (flag –17 set).
Example: Find the polynomial Q(x) such that
Q(x-2)=x
2
+3x+2.
Command: PTAYL(X^2+3*X+2, 2)
Result: X^2+7*X+12
PTPROP
Type: Function
Description: Returns the specified property for the specified element. It takes the element’s atomic number or
symbol as a name (with certain restrictions) and the property number. It returns the property,
usually a value or a string. It chooses to use or not use units according to the Units Usage flag
(flag 61: SI units if clear, no units if set). If you use PTPROP as an algebraic function, you must
use the symbol to define the element — you can’t use its atomic number.
See Appendix B for a full list of available properties.
Access: G PERIODIC TABLE PTPROP
Flags: Units Usage (61)
Input/Output:
Level 2 Level 1 Level 1
'symb' x
→
“string” or x or x_unit or 'name'
y x
→
“string” or x or x_unit or 'name'
Example 1: The command sequence 'Hg' 6 PTPROP returns "[Xe]4f14·5d10·6s2" .
Example 2: The command sequence 79 8 PTPROP returns 1337.58 when flag 61 is set.
See also: MOLWT, PERINFO, PERTBL
PURGE
Type: Command
Description: Purge Command: Purges the named variables or empty subdirectories from the current directory.
PURGE executed in a program does not save its argument for recovery by LASTARG.
To empty a named directory before purging it, use PGDIR.
To help prepare a list of variables for purging, use VARS.
Purging PICT replaces the current graphics object with a 0 × 0 graphics object.
If a list of objects (with global names, backup objects, library objects, or PICT) for purging
contains an invalid object, then the objects preceding the invalid object are purged, and the error
Bad Argument Type occurs.
To purge a library or backup object, tag the library number or backup name with the appropriate
port number (:n
port
), which must be in the range from 0 to 3. For a backup object, the port