HP 39gs_40gs_Mastering The Graphing Calculator_English_E_F2224-90010

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T
T
H
H
E
E
E
E
X
X
P
P
E
E
R
R
T
T
:
:
S
S
I
I
M
M
U
U
L
L
A
A
T
T
I
I
O
O
N
N
S
S
&
&
R
R
A
A
N
N
D
D
O
O
M
M
N
N
U
U
M
M
B
B
E
E
R
R
S
S
New columns as functions of old
You have already seen the use of one trick when we created a new column
C1 by storing 2*C1 into C2 using
the
HOME view. This can be used to create new columns as functions of any number of others. For example,
a set of data that you suspect is exponential could be ‘straightened’ by storing
LN(column) into a fresh
C3.
column. Changes of scale and origin can be investigated in this way by storing (say)
-2*C1 + 3 into C2.
You can even combine columns such as
C1 + C2
If you don’t particularly need to see the data as a fresh column, you can
use the
SYMB view to accomplish the same thing in a simpler way. For
example, the
SYMB view snapshot on the right would accomplish the
same thing as storing
2*C1 into C2. A histogram of H2 would look the
same as the one we produced earlier using the
HOME view, and the
command would give exactly the same results. The advantage
of this is that it takes much less memory if both columns need not be stored.
For the teacher this can be a handy way to create sets of data that conform to particular models. For
0.03x
example, if you would like a set of data that conforms to a model of
y
ˆ
=
2.5
e
then simply enter any
values randomly into
C1 and then, in HOME, perform the calculation 2.5*e^(0.03C1) C2. Of course, the
result will be a set of y values which exactly match the model and this is not desirable. The teacher should
now go through them and introduce some random error so that they are no longer a perfect fit.
Simulating Dice
The most common experiments in probability involve the rolling of dice. This can be simulated in the Statistics
aplet using the
MATH menu function MAKELIST. (For more detail see page 190)
The syntax is:
MAKELIST( expression, variable name, start, end, increment )
where
expression is the mathematical rule used to
generate the numbers.
variable name is the letter (X, Y etc.) that is to be
used in the expression (any other
letters will be taken as constants).
start is the first value variable name is to take.
end is the upper bound for variable name.
and
increment is the amount that variable name
should be incremented by in each
iteration.
For example:
MAKELIST(X2,X,1,10,2)
would produce { 1, 9, 25, 49, 81 } as
X went from 1 to 3 to 5 to …
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