HP 48GII

Full Command and Function Reference 3-127
Description: Predicted x-Value Command: Returns the predicted independent-variable value x
independent
, based
on the dependent-variable value y
dependent
, the currently selected statistical model, and the current
regression coefficients in the reserved variable ΣPAR.
The value is predicted using the regression coefficients most recently computed with LR and
stored in the reserved variable ΣPAR. For the linear statistical model, the equation used is this:
y
dependent
= (mx
independent
) + b
where m is the slope (the third element in ΣPAR) and b is the intercept (the fourth element in
ΣPAR).
For the other statistical models, the equations used by PREDX are listed in the LR entry.
If PREDX is executed without having previously generated regression coefficients in ΣPAR, a
default value of zero is used for both regression coefficients, and an error results.
Access: …µ
PREDX
Input/Output:
Level 1/Argument 1 Level 1/Item 1
y
dependent
→
x
independent
See also: COLΣ, CORR, COV, EXPFIT, ΣLINE, LINFIT, LOGFIT, LR, PREDY, PWRFIT, XCOL,
YCOL
PREDY
Type: Command
Description: Predicted y-Value Command: Returns the predicted dependent-variable value y
dependent
, based on
the independent-variable value x
independent
, the currently selected statistical model, and the current
regression coefficients in the reserved variable ΣPAR.
The value is predicted using the regression coefficients most recently computed with LR and
stored in the reserved variable ΣPAR. For the linear statistical model, the equation used is this:
y
dependent
= (mx
independent
) + b
where m is the slope (the third element in ΣPAR) and b is the intercept (the fourth element in
ΣPAR).
For the other statistical models, the equations used by PREDY are listed in the LR entry.
If PREDY is executed without having previously generated regression coefficients in ΣPAR, a
default value of zero is used for both regression coefficients–in this case PREDY will return 0
for statistical models LINFIT and LOGFIT, and error for statistical models EXPFIT and
PWRFIT.
Access: …µ
PREDY
Input/Output:
Level 1/Argument 1 Level 1/Item 1
x
independent
→
y
dependent
See also: COLΣ, CORR, COV, EXPFIT, ΣLINE, LINFIT, LOGFIT, LR, PREDX, PWRFIT, XCOL,
YCOL
PREVAL
CAS: Return difference between values of a function at two specified values of the current variable.
PREVPRIME
CAS: Given an integer, find the closest prime number smaller than the integer.