Lgstr – Texas Instruments TI-86 User Manual

Page 325

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Chapter 20: A to Z Function and Instruction Reference

313

20ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 313 of 118

20ATOZ.DOC TI-86, Chap 20, US English Bob Fedorisko Revised: 02/13/01 2:42 PM Printed: 02/13/01 3:05 PM Page 313 of 118

LgstR

STAT CALC menu

Built-in equation variables
such as y1, r1, and xt1 are
case-sensitive. Do not use
Y1, R1, and XT1.

LgstR

returns a tolMet

value that indicates if the
result meets the TI

-

86’s

internal tolerance.

If tolMet=1, the result is
within the internal
tolerance.

If tolmet=0, the result is
outside the internal
tolerance, although it
may be useful for general
purposes.

LgstR [

iterations

,]

xList

,

yList

,

frequencyList

,

equationVariable

Fits a logistic regression model (y=a/(1+be

cx

)+d) to real

data pairs in xList and yList and frequencies in
frequencyList

. The regression equation is stored to

equationVariable

, which must be a built-in equation

variable such as

y1

,

r1

, and

xt1

. The equation’s

coefficients always are stored as a list to built-in
variable

PRegC

.

The number of iterations is optional. If omitted, 64 is
the default. A large number of iterations may produce
more accurate results but may require longer
calculation times. A smaller number may produce less
accurate results but with shorter calculation times.

Values used for xList, yList, and frequencyList are
stored automatically to built-in variables

xStat

,

yStat

,

and

fStat

, respectively. The regression equation is

stored also to built-in equation variable

RegEq

.

In

Func

graphing mode:

{1,2,3,4,5,6}¶L1 b

{1 2 3 4 5 6}

{1,1.3,2.5,3.5,4.5,4.8}¶L2 b

{1 1.3 2.5 3.5 4.5 4…

LgstR L1,L2,y1 b

Plot1(1,L1,L2) b

Done

ZData b

LgstR [

iterations

,]

xList

,

yList

,

equationVariable

Uses frequencies of 1.

LgstR [

iterations

,]

xList

,

yList

,

frequencyList

Stores the regression equation to

RegEq

only.

LgstR [

iterations

,]

xList

,

yList

Uses frequencies of 1, and stores the regression
equation to

RegEq

only.

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